Apps, sites and tools people actually built, mostly solo with an AI agent, pulled from Reddit, Hacker News and elsewhere. Filtered to things you could build with what you already pay for.
23 Oct 2026
A web designer built a "what if I die" switch, and now sells it to clients as a reason to trust the studio
What it is
A dead man's switch for a one-person studio. It emails you once a week, and if you stop answering it works its way through a list of people you've chosen, ending with whoever needs to keep your clients' sites running.
Why it is useful
If you hold every client's domains, hosting and logins, nobody knows where any of it is the day you're in hospital. Peter Bishop, a web designer in New South Wales, lost their business that way in 2012. The switch now goes into their contracts, and they say clients treat it as a selling point when handing over their accounts.
What it looks like
Monday at 9am an email arrives with one button, "I am here: check in". Opening the email doesn't count (spam filters open links), you have to press it. Miss it and you get reminders at 24 and 48 hours. At 72 hours your next of kin gets "Is Sam all right?" with two buttons, "All fine" and "Something's wrong", each saying what it will do before they press. Only if they say something's wrong, or don't answer, do your lawyer and backup developer get the message you wrote for them, saying where the encrypted master document is. Check in at any point, even after it's fired, and everyone is told it was a false alarm. The dashboard draws the whole six-day countdown under your next check-in date.
How it was made
The builder wrote a long plain-English spec first (who gets told, in what order, after how long, and what counts as a real check-in), then had Claude Code build it from that, with 42 automated tests to prove the timings. It deliberately stores no passwords or documents, only messages saying where things are and who to call. It's one small PHP app with no database, plus a scheduled job (cron, the thing that runs a task every 15 minutes) that the installer writes for you. The advice is also to host it somewhere separate from the sites it protects, so one outage can't take both down.
What it would take you
An evening, and £0. You could run the original as it is, but the natural rebuild for you is a Cloudflare Worker with a Cron Trigger doing the 15-minute check, D1 holding the state, and Cloudflare's email sending for the messages. Your encrypted "where everything is" document is the real work, and it's worth doing anyway given how many client zones and logins run through you.
Wikipedia, but only the things within a half-hour walk of you
What it is
A single web page that shows you Wikipedia as if it only contained the places near you: the abbey you never knew was there, the old railway, the listed pub. Everything else is cut out.
Why it is useful
It's a ready-made "what's around here" guide that costs nothing to run and never goes out of date, because Wikipedia keeps it current. People in the thread were finding things a few streets away they'd never heard of.
What it looks like
You type a postcode or a place, or let it find you. It shows a Wikipedia-styled page listing everything geotagged within about a 30-minute walk, with distances, photos and a map. If fewer than 25 things are that close it widens to about six miles; if there are more than 500 it keeps the nearest 500. Links to articles that aren't nearby simply disappear, so you can only wander locally. Your location stays in your browser, and a link you share doesn't give it away.
How it was made
There's no server and no database. The page asks Wikipedia's free public search for "articles with coordinates within this radius of this point" (every geotagged article has a latitude and longitude), turns UK postcodes into coordinates with the free postcodes.io service, and looks up place names with Photon, a free OpenStreetMap search. One JavaScript file of about 50 KB does the lot, and saves your last place and units in the browser.
What it would take you
An evening, £0, and a Cloudflare Pages site. The obvious steal is a "within walking distance" page for a hotel or restaurant client, centred on the venue rather than the visitor, which writes itself from Wikipedia and stays current without anyone maintaining it. Credit Wikipedia, as its licence requires.
500 different animated clocks in one web page, and the kit that let Claude keep making more
What it is
A gallery of 500 working clocks, each telling the time a different way: Nixie tubes, Roman water clocks, Game of Life patterns, word clocks in other languages, a Pong game where the ball takes exactly one second per crossing. The whole thing is one 6.3 MB HTML file with no images, fonts or libraries.
Why it is useful
As a toy, it's lovely. As a method, it shows how to get an agent to produce hundreds of genuinely different things without repeating itself, which is the problem you hit with any batch of designs, social graphics or gallery layouts.
What it looks like
A grid of small live clocks in a random order each time you load it. Hover one for its name and a one-line description; click it and it fills half the screen, with "how to read it" and "how it works" notes beside it. A toolbar lets you search, filter by category, and fast-forward time up to 3,600 times normal speed to watch the clocks spin.
How it was made
Tom Gally wrote no code. After the first 100, Claude wrote itself a build kit: a register listing every clock already made in one line each (so new ones can't repeat an idea), a list of about 165 ideas not yet built, a brief for the builders, and a step-by-step playbook. Each round, one Claude acted as manager, split the work into batches of 20, and sent several Claude helpers (subagents) off in parallel to build them. A test script then opened every clock in a hidden browser, jumped the time about, and saved snapshots onto contact sheets, which the managing Claude looked at to check each one was readable. Weak ones went back for another go: 14 of the last 120. Every picture is drawn by code on a canvas, so nothing is downloaded and each clock is sharp at any size.
What it would take you
It runs on your Max plan, but don't copy the scale: the 500 took about 15 million tokens over four sessions and roughly 18 hours, and the builder says it ate a big chunk of that week's allowance. Steal the kit instead. "A register of what exists, a list of ideas, batches of 20 to parallel helpers, contact sheets for review" fits straight onto social graphics and portfolio layouts, and slots into the agents you already run.
Let Claude on your phone search your personal WhatsApp, from your own Cloudflare account
What it is
A small server that lives in your Cloudflare account and acts like a second WhatsApp Web login on your phone. Any Claude, including Claude on your phone, can then search and read your chats. It can't send anything.
Why it is useful
"What did Dana say about the flights?" or "Summarise the family group this week" answered from anywhere, without leaving a Mac switched on, and without a WhatsApp Business account. The builder wanted exactly that and found the only other options needed either Business or a server of their own.
What it looks like
You deploy it, open its web address, and scan a QR code with WhatsApp (Settings, Linked Devices) as you would for WhatsApp Web. It imports whatever history WhatsApp hands over, with a progress bar. Then you add it to Claude as a connector, sign in with a password, and ask questions in plain words. Your phone carries on as normal, notifications and all.
How it was made
It doesn't stay connected. When you ask something, and once a day at 4am, it logs in, collects what WhatsApp has queued since last time, saves it, and hangs up. Messages sit in a small database inside your Cloudflare account (a Durable Object, a little store that belongs to one app) with full-text search. The clever bit is names: a linked device doesn't get your contact list, so many chats show only a phone number. The server doesn't log into Google itself. It hands that job back to your agent, which looks the numbers up with whatever contacts tool it already has and saves the names. Every "no chat found" reply nudges the agent to do this.
What it would take you
An hour. It needs Cloudflare's Workers Paid plan (about $5 a month) because the first history import is heavy; skip that if you're already on it. Two honest caveats: it uses the unofficial WhatsApp Web protocol, which is against WhatsApp's terms (low risk for a read-only device, not zero), and the people you message never agreed to an AI reading their side. You already have WhatsApp tools running on the Mac; this is the version that works when the Mac's off and you're out.
SimCity, except every building needs planning permission and the neighbours object
What it is
A city-building game in the browser where you're the elected mayor rather than a god. Every apartment block, bus lane and factory goes through hearings, objections, appeals and lawsuits, and you face re-election every four years.
Why it is useful
It's the most popular build on Hacker News this week, and a good example of one person shipping a deep, polished game with Claude doing nearly all the code and the human doing the design. Anyone who's dealt with a planning department will get the joke in about thirty seconds.
What it looks like
You start with a hamlet at a crossroads or inherit someone else's mess. Rezone an empty lot for a 12-storey block and your inbox fills up: homeowners organise over parking and "neighbourhood character", a hearing trims it to six storeys, the smaller scheme stops paying, the developer wants a tax break, and four years later rents are still rising and both sides blame you. A seven-seat council votes, a local paper reports your scandals and your parking minimums, and heatmaps show which decision made which voters angry. No account and no download; saves stay on your computer and it works offline after the first visit.
How it was made
Peter Cai says it's "almost all Claude", with the human side focused on gameplay, art direction, mechanics and storytelling. It began with a library of hand-written story arcs for variety, then went back and wired them into the simulation once the city's details firmed up. The lesson from playtesting is worth stealing: the first version showed all the complexity at once, players bounced off it, so it switched to revealing the depth gradually. When players hit crashes, Claude was set to fall back to lower-quality textures on machines short of memory, and shipped fixes within hours of the comments.
What it would take you
Honestly, weeks rather than a weekend for something this deep, all on your Max plan and a static Cloudflare Pages site. The transferable part is smaller: a browser game or interactive explainer that saves to the visitor's own machine and works offline, for £0 hosting.
A pond of synthesised ducks, tuned by letting the AI listen to a real duck
What it is
A web page with a little pond of mallards (three hens, two drakes, two broods of ducklings) that go about their day, feeding, preening and calling to each other. Every quack is made from scratch by code as it happens. There isn't a single recording in it.
Why it is useful
Mostly it's a delight. But the way it was tuned is a method you could point at your own work: give the agent a real example and a way to measure the difference, then let it keep adjusting until the gap closes.
What it looks like
A map of the pond and a list of the ducks. You hear them around you (better on headphones, where each sound comes from where its duck is). A hen's quack sets off her mate; a duckling that wanders more than 4 m from its mother stops and peeps until she calls it back. Press "Throw peas" and the nearest ducks notice first, call, and race from pea to pea.
How it was made
The builder says audio is completely outside their skills and they contributed little beyond a few technical choices. They ran Claude in a loop: synthesise a quack, turn it into a spectrogram (a picture of a sound, showing which pitches are loud at each moment), compare that with the spectrogram of a real recorded duck, adjust the settings, go again. It worked well enough that a sound-recognition model rated the fake quack as more duck-like than the real one. The model underneath imitates a duck's voice box and bill opening on "qu-" and closing on "-ck", with small random wobbles so no two calls match.
What it would take you
£0 and an afternoon to try the idea on something of yours. The same loop works with a picture instead of a sound: give Claude a photo graded the way you like and a raw file, have it adjust settings, render, measure the difference against the reference, and repeat. It's a cheap way to get a starting look you'd then finish by eye.
Someone trained the AI writing habits out of a small model, on a MacBook Air
What it is
A small free AI model that writes without em dashes, "it's not X, it's Y", tidy lists of three or LinkedIn-style openers, and needs no special instructions to do it. It's a 2.5 GB download that runs on a laptop.
Why it is useful
The model itself is a curiosity. The useful part is how progress was measured, because it's the same fight you have in every humanise pass: getting rid of AI tells without the writing going strange in new ways.
What it looks like
The write-up shows side-by-side answers. Asked for a LinkedIn post about a new CRM, the original model opens "We're excited to announce a major step forward" and scores 223 on the author's slop meter; the trained one says "We switched to Salesforce last month and it's already changed how we handle customer calls" and scores 22. Human writing usually scores under 15. Underlined passages show which habit the meter caught.
How it was made
The author wrote a "slop score" from a style guide of AI habits, each weighted, counted per 1,000 words. A better-behaved setup answered 288 prompts, only the answers that passed were kept, and taught the small model to copy them (a LoRA, a small add-on that changes how a model writes). The lesson is in round two: the score fell to 9.9 but the writing got worse. Opinion pieces took no position, it invented "a study from the University of Technology Sydney", and it joined every sentence with ", which". So the author added task checks a word list can't do: does an opinion piece state a position early, is a personal piece in the first person, does an email open with a greeting, is it roughly the length asked for. The final model scores 12.5 and passes those 80% of the time. The write-up is honest that it still reads flat and invents names and places.
What it would take you
£0. You could run it on the Mac Studio tonight, but its voice is too flat for anything you'd publish. Steal the task-fit checks instead: your scanners already catch the tells, and this is the missing second half, a check that the fixed text still does what the brief asked.
Your own personal assistant, living free inside your own Cloudflare account
What it is
A private ChatGPT-style assistant that also keeps your tasks, notes and reminders, and the whole thing sits in your own Cloudflare account rather than on someone else's server. One command installs it, and it's meant to stay inside Cloudflare's free allowance for one person.
Why it is useful
No monthly subscription and nobody else holding your data. Reminders and routines still fire when the app is closed, and the tasks and notes keep working even on a day when the free AI quota runs out.
What it looks like
You open a web address that only you know, type your password and get a chat window. Tell it "remind me to chase the Grand invoice on Monday" and it shows a little "using tool" marker, then the reminder appears in an Automations tab. There's a Memory page listing what it knows about you, each fact editable, and if you say you sold your car it asks whether the old car is now a past fact. On Monday morning the reminder pops up as a normal phone notification.
How it was made
The clever bit is that there's no database server at all. Everything, from chats to tasks to the reminder timers, lives inside one Durable Object (a tiny always-available box of storage that Cloudflare keeps for you, with its own built-in alarm clock). The chat model is a free one on Workers AI, Cloudflare's own AI service, and only the handful of memories that matter to your question are sent along with each message. The back end has no public address at all: your browser only talks to a Pages site, which passes requests through a private connection. The installer is careful too: run it again after a failure and it picks up where it stopped, never deleting anything.
What it would take you
You could install it this afternoon for nothing with `npx create-talorys@latest`, or have Claude Code read the repo and build your own version that knows about your clients and your calendar. One caution from the thread: a commenter on a paid Workers plan was billed for Workers AI usage they thought was free, so check your Cloudflare usage page after the first week.
A 14-year-old built a Mac voice assistant that runs on your Claude plan and learns your shortcuts
What it is
Siri, if Siri were actually useful. Hold three keys, say what you want, and it does it on your Mac, using the Claude Max plan you already pay for instead of an API key.
Why it is useful
Everyday asks (open an app, play a playlist, search the web) never touch the AI and finish in under a second. Bigger jobs go to Claude and use about a fifth of a US cent of plan usage each. Anything that deletes, sends, buys or edits a file stops and asks you first.
What it looks like
You hold Control, Option and Space and say "make a new meeting with Claire for Thursday at two". A small box appears showing what it heard, then the steps as it clicks through Calendar for you. The first time it takes about 30 seconds. Ask again next week and it replays the same steps from memory in five to eight seconds, with no AI involved. Ask for something big like "find me USB-C hubs" and a little chip sits in the corner of the screen while a background agent works, and you can talk to it mid-job ("check HDMI too").
How it was made
Two ideas worth stealing. First, a fast lane: a list of simple commands is handled by plain code on the Mac (opening an app takes 0.08 seconds), and only what doesn't match goes to Claude through `claude -p` (Claude Code run as a one-shot command). Second, record once, replay forever: when Claude completes a task correctly, the exact clicks are saved as a shortcut, and if a saved shortcut later fails, Claude works out why and records a fresh one. Speech-to-text is Apple's own, done on the Mac, so it's free. The builder is in 9th grade.
What it would take you
Nothing to try it (it's free, needs macOS 26). The pattern is the real prize: you could add a "fast lane plus recorded shortcuts" layer to your own Mac set-up, so the things you ask Claude for every week stop costing a model call at all. A few evenings in Claude Code.
An email address for every company, each one locked to whoever writes first
What it is
A spam-proof inbox system. You give every shop, bank and newsletter its own address, and each address only ever accepts mail from the first company that uses it.
Why it is useful
When a company leaks or sells its mailing list, the list is worthless, because your address bounces everyone except the original sender. And you can see exactly who leaked it.
What it looks like
At a checkout you type `service-currys@yourname.clova.email`, an address you've just made up on the spot. Currys' receipt lands in an inbox called "service-currys", which has now locked itself to currys.co.uk. Six months later a spammer tries the same address and gets bounced. There are also throwaway inboxes you set to die after a day or a month, handy for a one-off download link.
How it was made
The trick is the "prefix" inbox. You claim one word, say "service", and then anything you tack on after it already works without setting it up first: `service-netflix`, `service$bank`, whatever you invent at the till. Whichever sender writes first owns that address for good (for Gmail and Outlook addresses it locks to the person, not the whole of Gmail). It also has an MCP server, so an AI agent can create inboxes and read mail. It's a solo build with a free tier and a 30 dollar a year paid plan.
What it would take you
You could build the core of this on Cloudflare for free. Cloudflare Email Routing can send every address on a domain to one small Worker; the Worker checks a list (kept in KV, Cloudflare's simple key-value store) of which sender owns which address, forwards the mail if it matches, and rejects it if not. Point it at a spare domain and you'd have it working in an evening, plus another evening for a little page listing your addresses and who owns each one.
A free, open-source Wispr Flow, made by someone who used to pay for Wispr Flow
What it is
A dictation app for Mac. Hold Option and Space, talk, and tidy text appears in whatever app you're typing in.
Why it is useful
It does the transcription on your own Mac, so there's no monthly fee and your recordings never leave the machine. The builder was an annual Wispr Flow subscriber who felt the accuracy had dropped, and built this as the replacement. If you pay for Wispr Flow, it's worth an afternoon's comparison.
What it looks like
You're in a WhatsApp Web chat, hold Option and Space and ramble "um so I think, I think Thursday works for the shoot". You let go and "I think Thursday works for the shoot." drops into the message box, with the ums and the repeated words gone. A settings page holds a custom word list (client names, "Padharo", "Cloudflare") and lets you pick a different writing style for each app, so Slack can be casual and email can be tidy. There's an optional meeting recorder that writes a summary afterwards.
How it was made
It strings together free speech recognition models that run on the Mac itself (Whisper, Parakeet or Apple's own), then a clean-up pass that strips filler words and applies your vocabulary list. The whole app is a 14 MB download, against roughly 150 to 200 MB for some rivals. Open source under the Apache licence.
What it would take you
Free to install, needs macOS 14 or later. If it holds up, that's a subscription you could cancel; your prompt-prep plugin already fixes dictation slips, and its dictionary could become BetterWispr's custom word list.
A site that tells you which native plants to grow where you're standing, and publishes its own AI bill
What it is
A garden planner for wildlife. You tell it where you are, how sunny the spot is and what the soil is like, and it gives you a list of native plants that suit it and what each one does for insects, birds and the ground.
Why it is useful
It replaces years of asking the same questions of books, plant societies and chatbots, and it answers from checked public data rather than whatever a chatbot makes up.
What it looks like
You open it on your phone in the garden, let it find your location, then step through numbered pages: sun, soil, and a goal like "soak up rain" or "stop erosion". The result is a list of plants with filters to hide ones that spread too far, have thorns or sting. It's quick, works offline once you've looked a spot up, and the first visit downloads about half a megabyte, less than one phone photo.
How it was made
Built almost entirely with Claude, with one deliberate rule: no AI at all when someone uses it. All the hard thinking was done once, while building, and baked into plain lists, so the site is just files on a server and your phone does the sums. Plain scripts (no AI) regularly go back to the original science sources and check every plant fact still holds. And there's a page that publishes exactly what building it with Claude cost, session by session, with tips the builder now follows to keep sessions short: scripts do the counting, long jobs start from a written checklist, and screenshots are cropped to the bit that changed. A short promo film was narrated by AI voices for about 2 dollars.
What it would take you
This is exactly your stack: plain static files on Cloudflare Pages, free to host. The method to steal for client sites is "AI at build time, never at run time": use Claude to research and fact-check once, write the answers into the page, and ship nothing that calls a model. A UK version for Southampton gardens is a weekend, if you can find the right open plant data.
A big arrow your AI agent can draw on your screen when it needs you to click something
What it is
A small Mac tool that lets Claude Code put a huge coloured arrow and a sign on top of every window, pointing at the exact button it needs you to press.
Why it is useful
When an agent hits a step only a human may do (an "Allow" box, a Keychain prompt, a two-factor code) it usually prints "please click Allow" in a terminal you aren't looking at. This points at the button instead, and can even read the sign aloud to call you back from the kettle.
What it looks like
You're half-watching a Claude session when a fat green arrow swoops in from the right of the screen, pointing at a switch in System Settings, with a sign reading "Ryan, switch this on: Terminal may control your Mac". You can still click straight through it. Once you've done it the arrow vanishes on its own. If the sign holds a code, it shows as a copy button: click, paste. It also does numbered how-tos, three arrows saying "1. Click Animate, 2. Add an Effect, 3. Press play".
How it was made
One small Swift program (Swift being Apple's own language) that draws a transparent sheet over everything and needs no special Mac permissions at all, because it only draws and never clicks or types. It finds buttons by the name the Mac gives them for screen readers, so the agent can say "point at Allow in System Settings" rather than working out coordinates. One command installs a skill so Claude Code knows how to use it. The builder spent a lot of effort making the first, too-polished arrows look rougher, to keep that "yes, that one, exactly that" feel.
What it would take you
Free: `brew install franzenzenhofer/tap/bigarrow`, then `bigarrow install-skill`. Ten minutes, and it fits a real gap in your set-up: your sessions already have to stop and wait for you on Keychain prompts.
Someone matched 700,000 land listings against government maps to find plots that really do border public land
What it is
A property search for one very specific thing: land for sale in the US that actually touches public land like national forest, checked against official boundary maps rather than taking the estate agent's word for it.
Why it is useful
Listings say "borders state land" all the time, and checking it means opening a county map and lining up boundaries by hand. This does that check for every listing in the country, every week, and says plainly when it can't be sure.
What it looks like
A map and a list. Each listing page shows the plot outline next to the public land, how far apart they are, and extras like the flood risk, wildfire risk, height above sea level and the nearest road. Where there's no official plot outline it says so and measures from a pin instead, and never claims a shared boundary it can't prove.
How it was made
The builder (a geospatial mapping background) made the decisions about what counts as "bordering" and which data to trust, and Claude Code wrote most of the code. Once a week a job pulls about 700,000 listings from a paid listings service, fetches each nearby plot's outline from free state and county map services where they exist (about 20 states) and a paid supplier elsewhere, then checks it against the US government's public-land map, filtered to open-access land over 50 acres. The hardest bit wasn't code at all: every state publishes its maps differently, and a couple of "open" ones turned out to be internal test servers.
What it would take you
The US data costs money (two paid data licences), so not this exact thing. But the shape of it, joining two datasets nobody has joined before and refreshing weekly, is very doable in the UK. Land Registry plot outlines and Natural England's open access land map are both free; property listings are the hard part, because Rightmove doesn't offer a public feed. Worth remembering as a pattern for a client: their data plus a free government dataset.
A budgeting app that admits when it isn't sure, instead of guessing your numbers
What it is
A Mac budgeting app you can ask questions in plain English ("how much did I spend on fuel in August?"), where the AI runs on your own machine and nothing leaves it.
Why it is useful
Chatbots are known for getting sums about money confidently wrong. This one was tested on 494 questions and got 5 wrong, down from about one in five before the fix below.
What it looks like
You drop in a bank statement CSV from any bank. Then you type a question and wait 12 to 14 seconds. You either get a number with the matching transactions underneath, or a plain "I'm not sure" when it couldn't be confident.
How it was made
The clever bit is splitting the job three ways. A tiny AI model only turns your question into a structured search ("category: fuel, month: August, total"). Ordinary code, not the AI, then does the actual adding up against your statement. A second, bigger model reads your question independently, and if the two readings don't match the app says it isn't sure rather than picking one. A small team ("we") wrote up the designs that failed along the way.
What it would take you
You don't need a budgeting app, but the pattern is worth stealing for anything where a wrong number would be embarrassing, like asking questions of the Padharo bookings or a client's analytics. Have Jev (which you already pay for) or Claude turn the question into a query, let a script do the maths, and get a second reading to check. Pennies per question.
A parent set out to make a cosy brick builder and, eight days later, had a multiplayer city
What it is
A free browser game that's somewhere between LEGO and GTA. A shared 3D city where everyone builds brick by brick, and you can drive cars, ride buses, fly from the airfield and race on a track.
Why it is useful
It's mostly proof of scale: one person and Claude Code made a playable online world in eight days, with the builder's 9-year-old as the main tester.
What it looks like
You open the site and you're standing in a blocky city with other players. Pick a brick, click to snap it onto the studs (the builder tuned how firmly bricks hold to feel like real ones). Outside the centre you can build anywhere with anyone, but anyone can knock your build down, unless you spend in-game coins to buy your own plot, where only you can add or remove bricks. There are graphics settings so it runs on weak laptops too.
How it was made
Claude Code on Opus 5.5 wrote it, using three.js (the standard library for 3D in a web browser), a small Node server to keep every player in sync, and SQLite, a database that is just one file, to remember every brick. The builder started small and kept saying "and now add..." until it had cars and planes.
What it would take you
The 3D part is free and runs on Pages. The always-on multiplayer server is the bit you'd move to Cloudflare, where a Durable Object can act as the city that everyone connects to. A week or two of evenings for something this big; a weekend for a smaller shared world, say a pin board guests add photos to at a Padharo event.
A darkroom timer made from an iPhone and a £20 smart plug
What it is
A darkroom printing timer that lives on your phone. Your enlarger plugs into a cheap Wi-Fi smart plug, and the phone switches it on and off to the second.
Why it is useful
Proper f-stop darkroom timers cost $300 or more. This does the same job, plus test strips, dodge and burn plans and split-grade printing, for under $50 including the plug. The builder measured it with slow-motion video and got 0.1 second accuracy, which is plenty when most prints need 4 to 60 seconds.
What it looks like
A black screen with dim red buttons, tested so it won't fog photo paper. You type in the plug's address once, then tap to expose. For a test strip it walks you through each step and clicks the light on for each band. Dodging and burning is laid out as a grid, so you plan which bits get extra light before you start, then the app runs the sequence for you.
How it was made
A film photographer printing in a bathroom darkroom realised the phone could already do the timing, it just needed a switch. They picked Shelly plugs because they have good documentation and accept plain commands over your home Wi-Fi, so there's no hub or cloud in the way. In their words it was "blindly vibe coded using Codex and Xcode" (Xcode being Apple's app-building program). It's free to use, with a one-off unlock of about $25 for the advanced tools.
What it would take you
The general trick is the one to steal: a £20 Shelly plug (the UK Gen2 model works) turns any mains gadget into something your phone can time or trigger, so it suits anything from a fan to a lamp in the studio. Claude Code can rebuild it as a small web page that runs on your Mac on the same Wi-Fi, which skips the App Store entirely. Shelly plugs can also be told to switch themselves off after a set number of seconds, which keeps the timing tight. An evening, plus the plug.
Turn any screen into a sign, where the web address is the whole app
What it is
A website that shows one message as big as the screen allows. You type the message, pick colours and an animation, and everything is stored in the link itself.
Why it is useful
Any old tablet, TV browser or spare laptop becomes a sign without installing anything. Share the link and you've shared the display. There's no account, no database and nothing to pay for, because there is nothing on a server to store.
What it looks like
You open the editor, type "Bar closes at 11", pick a black background with white text and a gentle pulse. The preview updates as you type. Copy the link, open it on the tablet by the door, and the words fill the screen edge to edge. It also does slides, countdowns and a QR code that can join people to the Wi-Fi, ring a number or open a map.
How it was made
The builder wanted to put a message on a tablet they could control remotely but couldn't touch. The fix: put the message after the # in the web address (the fragment). Browsers never send that part to the server, so one plain static page can show every possible message and never sees any of them. It's hosted on Cloudflare and caches well. After the Hacker News thread they added the ability to install it like an app so it works offline, and fixed bugs that only showed in Firefox.
What it would take you
One HTML file on Cloudflare Pages, free, an evening with Claude Code. It's an obvious one for Padharo events and the hospitality clients: a welcome screen, a Wi-Fi password QR or a countdown to the first dance, sent as a link the venue can open on any screen. The fragment trick also works for anything shareable that shouldn't touch a server.
A weather app that only speaks up when tonight is actually clear
What it is
A small Mac app in the menu bar for stargazers. It reads the forecast every half hour and sends exactly one alert, an hour before sunset, if there's a long enough clear spell to photograph in.
Why it is useful
It removes the nightly chore of reading cloud charts only to learn it's cloudy again. Silence means "don't bother". The builder lives on the edge of the Yorkshire Dales, where clear nights are rare enough to miss.
What it looks like
Most evenings, nothing happens. On a good one, a notification arrives before sunset with tonight's plan: which objects are up during the clear window, in order, with camera settings for each. A week view shows the next ten nights so you can pick the best. You can photograph your back garden with your phone so it knows which bits of sky the trees and houses block, and it'll suggest darker car parks nearby with a map.
How it was made
The forecast comes from two free weather services, 7Timer and Open-Meteo, which need no sign-up. The clever bit is the rule rather than the data: alert only when every hour of the dark window is clear, and stay quiet otherwise, so you trust it when it does go off. It's a native Mac app and the code is free on GitHub. The builder kept adding features from the thread's suggestions within a day, including aurora alerts and the nearest clear sky.
What it would take you
The same idea fits a photographer's diary far better than a stargazer's. A Cloudflare Worker that runs on a timer, looks at your outdoor shoots in Google Calendar, checks Open-Meteo for cloud, rain and wind at each location, and pushes to your phone only when something looks wrong the day before. Free, an evening. Open-Meteo's free tier is meant for non-commercial use, so check the terms if it ever becomes a client-facing feature.
Rembrandt, a free Lightroom replacement where you can type the edit you want
What it is
A free, open-source photo editor and library for Mac, Windows and Linux, built to do the everyday Lightroom jobs: RAW development, masks, healing, presets, batch editing.
Why it is useful
It costs nothing and doesn't lock you in. Edits are saved in the standard side-files (XMP) that Lightroom also reads, your originals are never touched, and it imports a Lightroom Classic catalogue with its edits, keywords and collections, then reports anything it couldn't bring over.
What it looks like
You press Cmd K and type "golden hour, shadows +25" or "paste the edits from the previous photo", and the sliders move on their own while you watch. You can also drag up or down directly on a part of the picture to lighten that tone. AI masks pick out the subject or the background, and denoise and 2x or 4x enlargements run quietly in the background, pausing while you work.
How it was made
The typed instructions aren't an AI chatbot. They're a fixed vocabulary of phrases mapped to slider moves, running on your own computer, which is why it's instant and free. The editing engine runs on the graphics card using the same tech as web pages, wrapped in a small desktop app (Tauri), and RAW files are read by a well-known open-source decoder. The builder modelled the colour maths on darktable, a more powerful but much harder free editor, because darktable's learning curve kept defeating them. There's also a mode that serves it from the computer holding your photos so you can edit from any browser on the house Wi-Fi.
What it would take you
Free to try today on a copy of one shoot. Still missing: print, book and web modules, face recognition and tethered shooting, and the downloads aren't signed yet, so macOS will ask you to approve it. The phrases-to-sliders trick is worth stealing on its own for any tool you build: it feels like AI and costs nothing per use.
Search every photo and every second of video on your Mac by describing it
What it is
A free Mac app that indexes your photo and video folders so you can type "dog on a beach at sunset" and land on the right picture, or the exact moment in a video.
Why it is useful
It finds things by what's in them, not by filename. It also reads any text visible in images, and searches the words people actually say in your videos. Nothing leaves your machine.
What it looks like
A search bar and a grid. Type a description and the matching photos appear, each with a little badge saying why it matched. Switch to Scenes and the results are video stills with a timecode; click one and the video opens at that second. A Dialogue mode finds an exact spoken line. You can pin a search as its own tab, like "screenshots" or "anything with an email address in it".
How it was made
It uses small open AI models that run on your own computer: one that understands what's in a picture, one (Whisper) that transcribes speech, and an OCR tool that reads text in images. They download once (about 435 MB) and then work offline. The builder is an iOS developer who wrote it all in JavaScript so it would be easy to move to other computers later. A commenter who built something similar gave the main warning: how often you sample video frames decides everything, and one frame a second across 12,000 videos takes days.
What it would take you
Free, installs with Homebrew. Point it at one finished shoot on the external drive first and see how long it takes before giving it the whole archive. A good way to find "that venue shot from two summers ago" without remembering which folder it's in.
An old LG TV's Plex app took 30 seconds to open, so its owner rebuilt it with Claude
What it is
A replacement Plex app for LG televisions, open source and free. On the builder's 2019 TV the profile screen now opens in about 3 seconds instead of 30, and scrolling runs smoothly at 60 frames a second.
Why it is useful
It brings an old TV back to life without buying a streaming stick, and it plays 4K, Dolby Vision and Atmos directly on the TV's own video chip.
What it looks like
The familiar Plex layout, a big banner of what you're halfway through and shelves underneath, but it keeps up with the remote. You sign in by scanning a QR code on the TV with your phone, pick your profile, and press play.
How it was made
The builder worked out why the official app was slow: it's really a web page running inside the TV's built-in browser, so no amount of tweaking could fix it. So they threw the browser away and drew the interface straight onto the TV's graphics chip. To learn how LG's own apps talk to the video hardware, they used Claude Code alongside Ghidra, a free tool that turns a finished program back into something readable. It started in C and moved mostly to Rust. It installs without hacking the TV, through LG's developer mode.
What it would take you
Claude Code plus free tools, but this is weeks of evenings, not one. The bit to steal is the diagnosis: when an official app on kit you own is slow, ask what it's really running on before trying to speed it up.
AI models painting in oils, one brushstroke program at a time
What it is
An online gallery and live studio where AI models paint pictures on a simulated canvas, mostly in the style of the German painter Caspar David Friedrich, without ever seeing one of his paintings.
Why it is useful
As a toy it's lovely. As a lesson it's sharper: it shows what these models reach for when left alone. Asked only to plan a painting, Claude Opus chose a jug with lemons six times out of six, and 31 of 65 titled paintings are set at evening, dusk, twilight or sunset.
What it looks like
A wall of finished paintings, each with the model's own note about it. A live page lets you watch a painter at work: it lays down a passage, steps back to look at the canvas, writes in its journal, then carries on.
How it was made
There's no image generator involved. Each model paints by writing code against a simulation of oil paint on linen, with bristle brushes, wet paint, drying time and glazes. Most of the 75 paintings were made at a virtual easel, a section at a time with a look in between, rather than in one go. In some rounds painters worked in a chain, each leaving written notes for the next but never their picture. The builder, Alice, runs it in numbered rounds and writes up what each change did.
What it would take you
Runs on Claude Code using your Max plan; comparing several rival models would need their own paid API keys. The method is the steal: give a model a tool, let it make a bit, look at the result, then carry on. That loop is the same one that makes AI-built web pages better.
A whole art history museum you can walk around in a browser, built from Wikipedia
What it is
A 3D museum in a web page, with a room for each period from Chinese painting through the Renaissance, Impressionism and Ukiyo-e to Pop Art, hung with real works.
Why it is useful
Wandering beats scrolling. You get a sense of how one period runs into the next that a list of images never gives.
What it looks like
You start in a hall with doorways labelled by movement and date. Walk through one with the arrow keys and the walls are hung with that era's paintings, each with its label. An Explore button lets you search for a particular artist.
How it was made
A Greek developer started it as a single prompt to an AI model, then spent a long time reworking it. The paintings and their details come straight from Wikipedia's free image library, which is why some are low resolution. Commenters suggested better art databases and an audio guide, and the builder is working through the list.
What it would take you
Free, a weekend, Cloudflare Pages. The obvious version for you is a walkable portfolio: one room per kind of shoot, your own photos on the walls, a link a client can wander round. Building the 3D room is the easy part for Claude Code now; choosing and grading the pictures is the real work.
How one founder got an AI-built website to look like a designer made it
What it is
A ten-minute write-up of how Yakko Majuri, who says they aren't a designer, built the Railcode homepage with Claude Fable and then kept getting asked which designer they'd hired. The site is a sky-blue amusement park with a rollercoaster along the bottom of the hero, nothing like the usual dark purple AI landing page.
Why it is useful
It's the problem you fight on every client site, written down as a process you can copy. They saved every prototype next to the prompt that made it, so you can follow the whole route from slop to finished page. The thread is worth a look too: several designers point out that this is simply the design process, and one says the glass panels still give it away.
What it looks like
The post is mostly short videos of each stage. Four ASCII and neon rollercoasters, a playable Rollercoaster Tycoon mini game that got binned, a thin strip of park rides added under the hero, then side-by-side copies of the same page with one or two things changed. One screenshot is a "playground" page with live controls for the grass, accent and background colours, which is how the green got picked.
How it was made
Four habits. Ask the agent for at least four versions of any idea, guide half of them and tell it to "go wild" on the rest, and ask for the idea on a scale from minimal to outlandish. Keep the whole site in one HTML file until the look is settled, because one file is quick to copy, tweak and compare, and only then split it into components. Never delete a copy. And for anything fiddly (colours, fonts, positions) have Claude build a little control page with sliders instead of asking for change after change. They also say they only use Anthropic models for design, because GPT models "really struggle even with specific directions".
What it would take you
Nothing new, just Claude Code on Max. The playground idea slots straight into your preview editor workflow. Free.
Pixel-art city windows at night, with lofi music made live in your browser
What it is
A website showing a night-time view over one of 25 cities (Paris, Tokyo, London, Cape Town and so on) in pixel art, with rain on the glass and an endless lofi soundtrack. Think of a YouTube "lofi beats to study to" stream that you can steer.
Why it is useful
It's a one-person passion project that pays its way several ways at once: billboards in the scenes you can buy, a job board, a Gumroad pack of the video loops and a Buy Me a Coffee link. Most of the top comments are people asking for their own city.
What it looks like
You land on Paris at the real local time, rain on an attic window. A side panel lets you pick a city from a globe or a grid, change the weather (drizzle, thunderstorm, snow, falling leaves), turn on a city tour that hops every 5 to 30 minutes or follows whichever city is nearest 1am, and set focus and sleep timers. A "passport" counts the cities you've visited.
How it was made
The builder, Safa Elmali, makes each city ahead of time: AI draws the pixel-art scene and a short animated loop of it. The music isn't a recording. It's generated in your browser by the Web Audio API (the browser's own sound engine), so it never repeats and costs nothing to stream. The weather is a separate layer, which is why, as the builder admits, you can have autumn leaves outside a Paris window.
What it would take you
darkroom for the scenes (free tier), your Kling credits for the loops, the site on Cloudflare Pages. A weekend for a handful of cities. The angle for you: the same trick for a client, say the view from Banana Wharf, changing with the real weather and time of day.
A working Enigma machine you can take apart in your browser, built with GPT Astra
What it is
An interactive 3D lesson on the Second World War cipher machine. You type on it, watch the current run through the wiring, and pull it apart piece by piece.
Why it is useful
The builder had watched two well-known YouTube explainers and still didn't get how the rotors stepped, so they built something they could press a hundred times. It's a template for any "how does this actually work" page, from a camera shutter to an espresso machine.
What it looks like
A 3D Enigma sits on the page with a chapter list down the side: send an encrypted message, the plugboard, inside one rotor, the reflector, the double step, put it back together. Each chapter turns the model to the right part and animates it while a few lines explain what you're looking at. There's a history section with period photographs too.
How it was made
Mostly with GPT Astra, from reference images and "hundreds of extremely detailed prompts", one part at a time. The clever bit: they had the AI build inspection tools first, little pages that measure and check where each part sits, so every gear and pawl could be checked for size and position instead of trusting the model's eye. They've promised to open-source it once the wiring on the rarer models has been checked.
What it would take you
Codex on your ChatGPT Pro (Astra or Sol), a free 3D library such as three.js, Cloudflare Pages. A long weekend for one object, longer if accuracy matters. Slow performance on phones was the main complaint in the thread, so test on yours early.
The whole Solar System live in a browser tab, down to 526,000 asteroids and every tracked satellite
What it is
A live 3D map of space as it is right now, at real scale, from the planets down to the Starlink satellites and the scrap metal circling Earth.
Why it is useful
It's built entirely from free public data that refreshes daily, and the builder says it took "a few evenings" as a by-product of another project. That's the pattern worth stealing: find an open dataset nobody has made nice to look at, and make it nice to look at.
What it looks like
Drag to spin, scroll to zoom, click anything for a card and its orbit, double-click to fly to it. A time slider runs forwards and backwards, and satellites appear and vanish by launch date. People in the thread found the ring of satellites parked 36,000 km up and noticed that almost one in three tracked spacecraft is a Starlink. During the thread the builder added an ambient mode with flybys, eclipses and generated music, full screen on F.
How it was made
Three free sources (CelesTrak for satellite orbits, NASA JPL's small-body database for asteroids and comets, JPL Horizons for spacecraft), pulled daily. The trick that keeps 526,000 asteroids smooth: the graphics card works out every asteroid's position every frame, so the main processor barely touches them. The 30 MB asteroid file loads in the background while you're already looking at the planets.
What it would take you
A Cloudflare Worker on a daily schedule to fetch the data into R2, Pages for the site, Claude Code for the rest. A few evenings, free. Closer to home, the same approach works for any public feed: tides, flights into Southampton, ships in the Solent.
Jevmem: your coding agent writes down what you decided, using the Jev you already pay for
What it is
A small add-on for Claude Code that keeps a running list of project decisions in a file called JEVMEM.md inside the project, and hands it back to Claude at the start of the next session.
Why it is useful
It fixes the "I said Postgres on Tuesday and on Thursday it invented SQLite again" problem, and the log lives in the project folder rather than in Claude's private memory, so it travels between tools and machines. Separately, the same week someone had Jev play Pokemon Red all the way to the Hall of Fame: 16,150 decisions for about $1.65, which gives you a feel for how cheap these small yes/no calls are.
What it looks like
You work as normal. After each message Jevmem asks Jev whether anything is worth keeping (a decision, a rule, a bug, a change of mind) and adds the keepers to the file. Reverse a decision and the old line is marked "superseded" rather than deleted. Next session, the live lines are slipped back into Claude's context.
How it was made
It hooks into Claude Code after every turn and asks Jev a few typed save-or-skip questions, which is exactly the job Jev is built for. The builder tested it on 66 messages against six frontier models: 98.5% right on save or skip (tied with Astra), at about 0.3 seconds and $0.000127 a decision, against 3 to 4 seconds for the big models. They're upfront that it's a single run they built themselves.
What it would take you
Nothing to build: `npm i -g jevmem` and your existing TypeSafe key. Worth putting side by side with your own memory setup. Your messages, with secrets stripped, do go to TypeSafe's API.
Think out loud through a chess game, and get back a narrated video of what you got wrong
What it is
A set of Claude Code skills that turns one of your chess games into a commented video, built around what you were actually thinking at the board.
Why it is useful
Normal chess analysis gives you scores and long strings of moves. This answers your own questions in plain words, and because every claim is checked against a proper chess engine it doesn't flatter you. The builder says Claude "would have a hard time" calling a move good when the engine says it's bad.
What it looks like
You play a slow game with a voice recorder running and think aloud (the builder did it in French). Afterwards you tell Claude Code to analyse the game and give it the lichess link and the mp3. About an hour later you get an annotated game file and a web page with an analysis board. Ask for a video and you get a 6 minute 49 second narrated walkthrough with arrows, a score gauge and subtitles, saying things like "at move eight you asked yourself whether the bishop belongs on c4 or e2".
How it was made
The clever bit is lining the voice notes up with the moves. Claude transcribes the recording on the computer (whisper.cpp), then uses the clock times saved in the game record to match each sentence to the move you were weighing up. Then several helper agents question the chess engine (Stockfish) the way a person would, "why not my move?", "what if Black just takes?", until each mistake makes sense, and a final pass re-reads the lot for errors. The video is built from a storyboard with free local text-to-speech.
What it would take you
It runs on Claude Max as it is, but the builder puts one game at about $15 at API prices, so it eats quota. The pattern is the steal: your own think-aloud recording, a tool that checks the facts, a narrated video at the end. Swap chess for a shoot (voice notes on set, matched to the photo timestamps) and you've got a client walkthrough or a teaching reel, voiced with `speak`.
A shopping list on a little e-ink screen on the fridge, synced to everyone's phone
What it is
A small e-ink touchscreen (the kind of display a Kindle uses) stuck to the fridge, showing the household shopping list grouped by supermarket aisle, plus a phone web page that edits the same list.
Why it is useful
The builder says it's the first home project their family actually uses every day. It was also a test of whether Claude could write the software for a brand-new gadget they'd never worked with, and they say they didn't hand-write any of the 2,400 lines.
What it looks like
The fridge screen shows the list by aisle, in the order you walk round the shop. Tap items off as they go in the basket, and the on-screen keyboard suggests things you've bought before. On your phone you add items, reorder the aisles and set when it syncs (nothing overnight, more at weekends). They also put a basic MCP connector on it, so an AI can help plan the week's meals straight onto the list.
How it was made
Fully vibe-coded with Claude Code. The skill was in handling e-ink: quick partial redraws for taps, a full refresh every 10 changes to stop ghosting, and Wi-Fi switched on only while syncing so the battery lasts. A small server in the middle holds the list, and the first time it sees an item it asks Claude which aisle it belongs in; move it by hand and your choice sticks.
What it would take you
An M5Stack PaperMono at $55 to $65 (out of stock on M5Stack's own shop when checked), Claude Code, and a Worker with a D1 database in place of their home server. A weekend. The client version: a specials or stock board behind a bar that staff update from their phones.
A private Google Photos that keeps your pictures on Cloudflare R2, kept alive by Claude Code
What it is
Noodle Gallery is a Google Photos replacement you run yourself. It's a copy of Immich, the popular self-hosted photo app, with a pile of features bolted on that Immich's own team wouldn't take.
Why it is useful
Plain Immich keeps photos on the disk of whatever box it runs on. Noodle can store them in cheap cloud storage instead, including Cloudflare R2, and it fixes Immich's habit of treating one person as three different people when their face turns up in your library, your partner's library and a shared album. For a photographer with 20 years of files, that's a searchable archive with face search that doesn't rent your library back to you.
What it looks like
A timeline of your photos you can zoom out to years or months, a People page where each person appears once, and a Cmd+K search bar where you type "Sarah, Portugal, 2019, Fujifilm" and the filters fill in as you go. Near-miss faces the recogniser wasn't sure about turn up as a banner on the right person, and you tap same, different or ignore. Shared Spaces work like a family timeline that several people add to, with roles and an activity log.
How it was made
The clever bit is how a tiny project keeps up with a big one. Immich ships updates constantly, so every time a new release lands, the fork's changes are replayed on top of it (a "rolling rebase"), and the team built a command that shows only what that replay changed, since the raw diff against Immich runs to about 750,000 lines. The README says it's written "with a lot of help from AI coding tools (Claude Code and Codex)", with humans leading ideas, testing and debugging, and 36 of the last 40 commits credit Claude. One HN commenter flagged the flip side: hundreds of commits in a few weeks and no outside contributors, so they're waiting to see if it holds up.
What it would take you
Nothing to build if you just want it: it's free and open source (AGPL), runs in Docker on a Mac or a cheap mini PC, and R2 storage costs about 1.5 US cents per GB a month (a 2 TB archive is roughly 30 dollars a month). The steal for your own work is the method: fork an open-source app that's 90% right, have Claude add the missing 10%, and replay your changes on each new release.
A dead-man's switch for your scheduled jobs, which only speaks up when a job goes quiet
What it is
Sigabrt is a tiny monitoring service built by one person. Each of your automated jobs "checks in" when it finishes, and if a check-in doesn't arrive on time, you get an email or an ntfy push.
Why it is useful
Most alerts fire when a job fails. This catches the worse case, the job that never ran at all (the Mac was asleep, the drive wasn't mounted, the task silently stopped being scheduled), which nothing else will tell you about. The hosted version is free for one job and 15 euros a month after that.
What it looks like
You create an endpoint called, say, "nightly-backup", say it should report every 24 hours and that you'll forgive it 15 minutes late. You get a web address, and you add one line to the end of the job that visits it. The dashboard shows three nights of green ticks, then "Thu 03:15, nothing arrived, email sent". There's even a read-only view you open from the terminal with `ssh sigabrt.dev`.
How it was made
The whole idea is inverted monitoring: silence is the alarm. The job does its work, then calls a web address only if the work succeeded, so one line of code covers "crashed", "never started" and "machine was off". The service just remembers when each job last checked in and runs a timer. In the thread, the builder's own backlog adds a "started" signal for long jobs, and other people pointed at free equivalents like healthchecks.io.
What it would take you
An evening. A Cloudflare Worker gives each job a check-in address, KV (Cloudflare's small key-value store) remembers the last check-in time, and a Worker cron trigger (a built-in timer) looks every few minutes for anything overdue and fires your existing `claude-push`/ntfy alert. Free tier, zero pounds. It would sit neatly on top of every scheduled task you already run, including this digest.
Send a client a locked file that unlocks itself in any web browser, with nothing to install
What it is
A tool that turns any file into a single password-protected web page. The recipient double-clicks it, types the password and downloads the original. Think of an encrypted zip that doesn't need the recipient to have any zip software.
Why it is useful
Contracts, invoices, a raw file for a picky client, anything you don't want sitting readable in an inbox. It works offline, the file never touches a server, and there's no account for the client to make.
What it looks like
You open the tool, pick a file, type a password and hit Save. Out comes an HTML file. Your client opens it in Chrome or Safari, sees a password box, hits Next, checks the file name and size, then Download. The demo GIF on the repo shows the whole thing in about ten seconds.
How it was made
The trick is that the page carries both the locked file and the code that unlocks it, packed so it can also be opened with standard tools (it uses the same encryption standard as signed email, and even plain `openssl` can open it without the page). The builder took the idea from old "self-extracting archives", the .exe files that unzipped themselves. HN commenters raised two fair points: you still have to send the password by another route (WhatsApp, a call), and the recipient has to trust the page they've been sent.
What it would take you
Free to use today (Apache licence, live demo online). Building your own version is an evening with Claude Code, since browsers now do AES encryption natively: a single-file page on Cloudflare Pages that outputs locked HTML files, perhaps branded for your studio. Cost: nothing.
A two-person company built their own support desk, sprint planner and deploy tool, and wrote down how they stop them rotting
What it is
A write-up from Geocodio (just two people for nearly ten years) about replacing scattered scripts and SaaS tools with proper internal apps built with Claude, and the rules that keep those apps maintainable.
Why it is useful
It answers the question you'll hit once you've built a dozen tools for yourself: how do you keep them all working? And it gives three plain questions for deciding what to build and what to keep paying for.
What it looks like
Screenshots of their apps: a deploy dashboard showing which version each server runs, a sprint planner called Bullpen, a support desk called Atlas that pulls billing, account and history into one screen, and Yak, an agent that picks up small jobs from Slack and returns a finished change with a recorded walkthrough. Every tool has its own little documentation site with screenshots.
How it was made
The method is the valuable bit. Weeks of planning, hours of building. They pick a plan apart with Matt Pocock's "Grill Me" skill, which questions it until the weak parts fall out, mock up the screens before building anything, and use Fable for the planning. All their apps share one set of design parts, so none of them grows its own look. And every project's CLAUDE.md has a rule that any change affecting the docs means Claude must update the docs in the same go. Their build-or-buy test: do we actually know this domain, what happens if it's down for a day, and does the value come from plugging into our own data? Email stays with a paid provider for exactly that reason.
What it would take you
Nothing to buy. It's a playbook: copy the "update the docs" rule into your project CLAUDE.md files today, and run the three questions on the next SaaS you're tempted to replace. Two of their tools (Yak and Treehouse) are free and open source if you want to look under the bonnet.
Every 24/7 live camera on YouTube, pinned to a spinning globe
What it is
LiveWorld is a globe you spin to drop in on live webcams around the world: sea otters at Seattle Aquarium, airport aprons, train stations, volcanoes. One person built it in two weeks.
Why it is useful
YouTube has thousands of round-the-clock live streams scattered across random channels where nobody finds them. Putting them on a map turns a pile of links into something you can wander around, and it costs the builder almost nothing to run because YouTube hosts and streams all the video.
What it looks like
A satellite globe covered in pins. Tap one and the stream plays right there, with a small chat for whoever else is watching the same view. There's a "Feeling lucky" button, favourites, ambient audio, and a submit form for adding cameras. It launched with 641 cameras and now claims about 2,100.
How it was made
The content is the product, and the builder let the crowd fix it. HN readers found pins in the wrong city (a cam in Ohio shown in Chicago, Toronto filed under California) and dropped in missing cams, and he replied with fixes the same night, added each wrong pin to a test list so it couldn't come back, and promised a "right-click the globe to drop a pin" submit flow to replace the long form. Money comes from donations and a few ads.
What it would take you
A weekend. Plain HTML and JavaScript with a free globe or map library, YouTube's free embed player, and a list of streams with coordinates kept in D1 (Cloudflare's database), all on Cloudflare Pages for nothing. The angle for you: the same pattern for one place, for instance every live cam, sunrise spot and photo location around the Solent on one map.
A font workshop that makes deliberately cursed typefaces, like Times New Roman with every seventh letter in Arial
What it is
Bastardica is a joke font maker. Upload two fonts and it mixes them into one real font file that swaps in the second font every few letters. It started from Times New Bastard, a famous prank font.
Why it is useful
Mostly for fun (ransom-note headers, pranking a designer friend with Helvetica that's secretly one-third Arial), but it's also a genuinely usable effect for a poster or a playful brand, and it shows you can do heavyweight font editing in a browser tab with no upload.
What it looks like
Two upload boxes, one for the base font and one for the mix-in, a "swap every Nth letter" setting, and sliders to scale, nudge and slant the mixed-in letters so they sit on the same line. A preview line updates live as you type, and there are presets like "Temu Sans" and "Royal Ransom Note". Download gives you a normal font that works in browsers, Figma and print.
How it was made
The clever bit is using a font's own built-in letter-joining feature (ligatures, what turns "fi" into one joined shape) as a swap rule, so the font itself decides which letters to replace and every app just follows it. The editing runs on Python inside the browser tab (via a free tool called Pyodide), so fonts never leave your machine. The builder's tip: use prime numbers like 5 and 7 for the gaps, so mixed fonts collide less often.
What it would take you
Free to use now. Rebuilding something like it is a weekend with Claude Code on Cloudflare Pages at no cost, and the same trick (a font that swaps words or letters on its own) could make a memorable one-off title face for a client campaign. Check both fonts' licences before using a mix commercially.
A quiet koi pond on a web page, where each fish is another person watching, built by someone who can't write JavaScript
What it is
koi.rest is a calm little website: a hand-painted pond, soft water sounds and koi drifting about. Every fish beyond the first three is another visitor who has the page open at that moment.
Why it is useful
It's a proof more than a product. Paul, the builder, has ADHD, had just lost his job, and had sat on the idea for ages because he doesn't know JavaScript. He decided "good enough" beat "perfect", directed an AI to write all the code, and did the drawing, testing and taste himself. It's the clearest example this week of an idea going from head to live site without the builder writing code.
What it looks like
A landing screen with his painting of a koi and an Enter button. Inside, the pond fills the screen, fish glide around, a counter shows how many people are there, and new visitors pop in as new fish. There's deliberately nothing to click: the point is to do nothing for a minute.
How it was made
One cheap trick carries the "together" feeling. Instead of syncing every fish's movement between visitors (hard), the server only counts who is connected, and each browser spawns its own fish for that number, with three always present so nobody is ever alone in the pond. The HN crowd gave him a free QA pass: it stuttered under launch traffic and his host started refusing requests, and people asked for fish to fade in rather than pop, and for a solo mode without other visitors.
What it would take you
An evening. The visitor count is exactly what Cloudflare's Durable Objects (a small always-on counter living on Cloudflare) are for, and the rest is a single HTML page with canvas animation. The Durable Object needs the 5 dollar a month Workers plan if you're not on it; everything else is free. The same idea works for a photo gallery that shows how many people are browsing a client's wedding album right now.
A picture frame that listens to the garden and draws whichever birds it hears
What it is
A framed print on the windowsill that changes itself. A microphone outside picks up birdsong, software works out which species made it, and the frame redraws with a hand-cut 1800s engraving of that exact bird.
Why it is useful
As an object it's just lovely, and it took 2,287 points on Hacker News on charm alone. The pattern underneath is the useful bit though: a quiet screen in a room showing something true about that room right now, with no app, no account, and nothing leaving the house.
What it looks like
An A4 frame on a kitchen windowsill, matte and papery rather than glowing. Six birds sit arranged on a textured paper background, the larger ones pulled toward the centre and scaled by their actual body weight. Hear nothing for a while and you get a bare perch. It only redraws when the set of birds changes, so most of the time it just sits there looking like a print.
How it was made
The clever move is that he didn't build the hard part. Identifying a bird from its song is done by BirdNET-Go, free open-source software that already exists and runs on the little computer in the frame itself, so nothing goes off to a cloud service. His own code just asks it what it has heard, picks the matching pictures, and lays them out. The art is 800-odd cutouts across more than 400 species, every one cut by hand from a real out-of-copyright plate, deliberately not generated (some retouched with AI, none created by it). Two nice details for anything on e-ink: the finished collage gets reduced to the six colours the panel can actually print, and it only redraws when the birds change, because an e-ink refresh is slow and you can watch it happen.
What it would take you
A Raspberry Pi 5, a mic, an A4 frame and an Inky Impression e-ink panel. It comes in 4.0in, 7.3in and the 13.3in he used, which is nearly A4 and the expensive one, so budget accordingly and check Pimoroni for the current price. The software is free and there's no API bill, because the classifier runs locally. It also runs with no panel at all, as a web page on any screen, which is the cheap way to try it. The version that transfers to your work is the same shape with a different input: a screen in a restaurant showing what came in this morning, or a frame in the studio cycling the newest gallery.
A machine you can walk around inside, built to explain one piece of software
What it is
A web page that turns an invisible bit of server software into an explorable engine room, with decks you can look around, parts you can click, and experiments you can run.
Why it is useful
The subject doesn't matter and you'll never need it. The technique does. Turning a process into a place, where where-a-thing-sits tells you what it is, is the most persuasive way to explain anything complicated, and it works just as well for how a kitchen runs at service or how a booking moves from enquiry to table.
What it looks like
A dark control-room interface. Live counters along the top (8 keys, about 128 KiB allocated, model time 0.2 seconds). Down the page, labelled decks stacked like floors of a building: outside clients at the top, then the running program, then the data, then memory, then the operating system, then the physical disk at the bottom. Every part is clickable. At the bottom sit four runnable experiments, including one where you send a command and watch the route it takes, and one that shows why memory stays high after you've deleted things.
How it was made
It's a normal web page with a small simulation running behind it. The layout is doing the arguing: everything is stacked in the real order, from outside the machine down to the disk, so the diagram teaches you the hierarchy before you've read a word. The numbers along the top aren't decoration either, they move as you poke at it, which is what makes it feel like a machine rather than an illustration. As far as you can tell from using it, the whole thing runs in the browser with nothing installed.
What it would take you
Plain HTML, CSS and JavaScript on a Cloudflare Page, so nothing to run and nothing to pay. The code isn't the work. The work is deciding what the layers are and what each experiment proves, which is a couple of hours of thinking and then an evening of building for a simple one. The obvious client use is a page that shows a process instead of describing it in a paragraph nobody reads.
An app you can send someone like a Word document, with its data already inside
What it is
A way of packing a small web app and everything it has saved into a single file you can email, AirDrop or drop in a chat. The other person taps it and it opens, with the data already in it.
Why it is useful
It goes at a gap that's got worse as building got easier. Knocking up a little tool as a web page takes minutes now, but the moment it needs to remember anything you're into hosting, accounts and a database. This keeps a tracker, a price list or a job log as a file you own, the way a spreadsheet is a file you own.
What it looks like
You describe what you want and get back a single file ending in .capsule. Open it and you get what looks like an ordinary small app window, your data already loaded. Move it to a USB stick or your cloud drive and it's still the same document, same interface, same contents. Anything in it can come back out as CSV or JSON.
How it was made
The file is a SQLite database, the small self-contained database that already sits inside your phone and your browser, with the page's HTML, images and other assets stored inside it alongside the data. His own comparison is the right one: a spreadsheet is also just an interface plus its data in one file. It's written in Rust with Tauri, a toolkit for wrapping a web page as a proper desktop app without shipping a whole copy of Chrome with it, and a capsule can't reach the network unless you allow it. The Hacker News thread went hard at the obvious catch, and it's fair: the recipient has to install the free player first, which is friction a plain HTML file doesn't have.
What it would take you
Nothing, it's free, with players for Mac, Windows and Linux. The idea is worth more than the product for your kind of work: a job sheet or a quote calculator that a client keeps as a file rather than as yet another login. Spend an hour on the examples on the site before deciding whether the install step kills it.
A flight simulator where you aren't the pilot, you're in seat 14A
What it is
Pick any two airports in the world and take the flight as a passenger. Real terrain out of the window, real weather, and the sun in the right place for the actual time of day.
Why it is useful
It started as a joke and found a real use by accident. In the comments, several people who are frightened of flying said this is the training they'd actually wanted, because cockpit simulators teach you to be a pilot and their problem is being stuck in a seat with no control at all. One had paid for simulator training with a pilot and said it missed the point entirely. That's the lesson worth taking: a build with one strong idea, done properly, finds uses its maker never planned.
What it looks like
It opens on a dark world map scattered with airport codes, asking where you want to fly to, with a from box and a to box. Pick a pair, hit continue, and you get the window seat: shade up or down, tray table, seatbelt. A recent update added legs, so you can now get up and go to the toilet on the long ones.
How it was made
It's a Next.js web app using Esri's satellite imagery for the ground. The thing that makes it work isn't technical, it's the discipline. This isn't a flight simulator with a passenger mode bolted on, and everything you're allowed to do is something a passenger can do. The atmosphere comes almost entirely from the boring stuff, the shade and the tray table and the walk to the toilet, not from the scenery.
What it would take you
Ordinary web work with tools you already have, and the only running cost is map tiles, where the free Esri and OpenStreetMap tiers cover a hobby project comfortably. The hard part is holding one idea and refusing every feature that sits outside it, which is the bit most builds fail at, and it costs nothing but nerve.
Someone measured how much screen a browser actually gives you, and it's less than you think
What it is
A small research site that measured real browser windows rather than screen sizes, then published the spread with a calculator you can test your own layout against.
Why it is useful
One number is worth the visit. A 1080p monitor doesn't give you 1080 pixels of page height, it gives about 920 once the browser's own chrome is taken off, and 1920 by 920 is the single most common desktop pairing in the sample at 11.7%. The median mobile width is 400px. So a hero built to fill 1080 is already scrolling for most people, which is a thing worth knowing before you design the next one. The honest caveat, which the site states itself: it's 962 qualified observations from people who visited a screen-size tool, so use it to test layout constraints, not to estimate market share.
What it looks like
A report page with a calculator at the top. Type in a content width or a starting page height and it tells you what share of observed sessions would fit it. Below that, a table of how many observations came from each device type, then a row of actual viewport shapes all drawn at the same height so you can see the aspect ratios sitting next to each other.
How it was made
Not clever at all, and that's the interesting part. He already runs a screen-size checking tool, so the data was a by-product he happened to be sitting on. The work went into the honesty: publishing the exclusion rules (old tablet readings thrown out because the original classifier could mistake a touchscreen desktop for a tablet), setting a minimum sample before a category gets published at all (tablets have none, so nothing is published for them), and saying on the page what the numbers can't be used for. That's what makes a small dataset trustworthy rather than embarrassing.
What it would take you
Nothing to build, just take the number. 920px is the height that should be in your head for hero sections, and it's worth sitting alongside 1920x1080 in the visual QC pass. The build pattern is one you could run though: a free tool that quietly records one measurement, and a published report off the back of it that becomes the thing people link to.
A place to see how other people have actually set up their AI tools
What it is
A community directory where builders publish their working setup: which tools, which agent, which skills, which workflow. One bloke built it because he couldn't work out from scattered posts what everybody else had figured out.
Why it is useful
Two ways. As a resource it's a shortcut to other people's configurations, which is otherwise guesswork pieced together from screenshots. As a build it's the cleanest example going of the most reliable small-site idea there is: find a thing people keep posting in fragments, and give it a proper home.
What it looks like
A plain page written in his own voice, opening with "What's the craic with your AI setup?", his own setup published as the first entry so the place isn't empty, and a community list behind a sign-in. Adding yours is the only thing it asks you to do.
How it was made
Ordinary web app work, nothing exotic in it. The craft is entirely in the framing. The homepage opens by admitting he hasn't got his own setup figured out either, lists the things that confuse him by name, and says out loud that this might well end up a community of one. That honesty is most of why it got 213 points, and it's a better opening than any confident pitch would have been.
What it would take you
Directly buildable on Cloudflare Pages with D1 holding the entries, free at this size, an evening or two for a first version. The move worth stealing isn't the code, it's the first-person opening that admits what it doesn't know. It reads as human because it is, and it costs nothing.
People are pointing agents at kit they already own and unlocking things the manufacturer disabled
What it is
Not one build, a pile of them in one thread. Someone got an agent to work out how their office printer talks and write working software for it, and the comments filled up with people who'd done the same to other locked-down hardware.
Why it is useful
It's a recurring trick now rather than a one-off, and the examples are better than the original post. A Samsung monitor whose second display output the manufacturer never bothered to wire up properly: the model read the firmware, worked out which compiler built it, changed the logic, repackaged it, and the owner gambled on flashing it, and it worked. An LG laptop whose fan speeds are locked behind LG's own control app, unlocked in under twenty minutes. An analogue synth whose firmware was pulled off it, its undocumented instruction set worked out, the whole device emulated and turned into a plugin you can load in music software.
What it looks like
Almost nothing to look at. It's a long conversation with an agent, feeding it firmware dumps, captured traffic and disassembled code, and asking it what the pattern is.
How it was made
The reason this is newly possible is that these problems have no answer online to look up. As one person put it, there was no prior code and no niche forum thread for what he was doing, so the model had to generalise from scratch. That's the actual shift: agents have got good enough at reading unfamiliar binary and undocumented protocols to work out a format nobody ever wrote down.
What it would take you
Nothing beyond time on the plans you already pay for, and it works on either Claude or Codex. Two warnings from the thread itself, both real. Flashing modified firmware bricks hardware, and the man who did it said so plainly in his own post. And one dry comment is worth keeping in mind before you start: the moment you have a custom driver, you maintain it forever.
A free image editor for Mac and Windows, described rather than written, for about 2,000 dollars of agent time
What it is
A desktop photo editor, free and working offline, built by someone describing what he wanted to GPT Astra over an extended run instead of writing it himself.
Why it is useful
The honest numbers are the reason to read it. He says it cost roughly 2,000 dollars in tokens, it got 170 users on day one, and he calls it usable but buggy and unstable. The comments agreed with that last part, firmly.
What it looks like
A normal desktop editor window with builds for Mac, Windows and Ubuntu, free, working with no internet connection.
How it was made
By description, over a long run, and two things came out of the thread worth keeping. First the cost: that 2,000 dollars is metered API spend, not a subscription. On ChatGPT Pro the same work wouldn't bill per token, but it would still eat several weeks of allowance rather than an evening, so treat "vibe coded" at this scale as a real commitment. Second the reception: saying it was vibe coded lost him the room. More than one commenter said that mention alone cost the app its credibility, and the recurring practical complaint was the familiar one, that it works right up until it doesn't, because the person describing it can't always tell what he forgot to specify.
What it would take you
Not this, and not at this scale. Take it as calibration instead. Ambitious desktop software built by description is genuinely possible now and genuinely expensive in agent time, and whether you say out loud how it was made is a marketing decision rather than a technical one.