What I am building with AI, in the open. Small products and routines for real problems, each one rated for how cool it is, how many people it helps, and how well AI can build it today. The full case studies, prompts and build notes live behind the studio door.
Built, recorded or posted. Running in my life or someone else’s.
Histoline is a comparative timeline spanning seventeen civilizations from 3500 BC to 2026. Pick a year and see what every culture was doing at once. Built for people who want world history without a single country's point of view, it names contested events in each community's own terms rather than picking a side.
A daily routine that looks at what actually shipped across your projects, decides honestly whether it's worth posting about, and writes a draft post in your own voice, sending a short verdict to approve or skip. Built for anyone building in public who keeps meaning to post and doesn't.
A restaurant map where every pin is backed by a chef, critic, or Michelin quote with its source, instead of a star average. Built for people who don't trust crowd ratings and want a specific person's opinion before they go. It's live on the App Store and at getgoodfinds.com, starting in Hong Kong with a global catalog behind it.
A daily routine drives my app in a simulator like a real user, records the walkthrough, adds captions, and queues the finished clip to my social accounts. Built for me, the solo person behind an app with no time to film and edit demos by hand. It turns one written flow into a ready-to-post video overnight.
The board behind everything else on this list. It is a kanban that collects product ideas from creators I follow, scores each one, and moves it through lanes from Ideas to Posted. A build-this button flags a card so Claude Code can build it and log what happened, which is how every other case study here got written.
Each day, a post takes the outfit a celebrity just wore in a magazine photo and pairs it with similar pieces from a real shopping catalog: one match for the top, one for the bag, one for the shoes. Anyone who wants a look but not the celebrity price gets a shortcut to something close.
A blog that publishes a page about where a well-known chef, critic, or regular actually eats in a given city, built entirely from quotes they gave to real outlets, each one linked back to its source. Built for anyone planning where to eat who trusts a named person's word over a generic listicle.
Scoped and queued. Claude builds these in order.
For anyone who signs up for a free trial and forgets to cancel, this checks the inbox once a month for new subscriptions, then asks over chat whether to set a reminder before renewal. Say yes and a calendar reminder appears with the cancel link already in it. Nothing gets cancelled automatically; it only asks and remembers.
Every weekday morning, an assistant reads your calendar, inbox and messages and sends a short brief with the three things that actually need your attention today, plus a quick prep note for your first meeting. Built for anyone juggling many channels who starts the day already behind. It replaces ten minutes of triage with something already sorted.
A writing check that would run on anything before it goes out, a post, a caption, a longer piece. It would flag the tics that make AI-assisted writing sound the same as everyone else's, stock phrases, tidy sets of three, a closing line that just repeats the opening, and return a cleaned version plus a score, so what ships still sounds like the person who wrote it.
A daily check would watch the numbers that matter for a small product: signups, imports, usage. When one moves more than expected, it would look at what changed recently, a release, an incident, a campaign, and write a plain-English explanation with how confident it is, so a busy founder wouldn't have to dig for the story behind a chart.
The backlog. Scored for how cool it is, how many people it helps and how easy it is to copy, plus how well AI can build it today.
A command that turns a rambling voice note into something usable: a task list, the decisions buried in it, a few content ideas, and a callout when you keep mentioning the same unfinished thing across multiple dumps. Built for anyone who thinks out loud and rarely turns it into action.
For anyone making videos who wants to study what's working for other creators, this takes a channel handle and returns what its best recent videos have in common: hook patterns, typical length, posting cadence, and a few ideas that borrow a working pattern for your own channel. It's research on demand, not another habit of scrolling and hoping something transfers.
A letter-writing tool for when something you bought is faulty or a service let you down. Describe what happened and it drafts a complaint that names the consumer right you can point to, states the remedy you want, and gets firmer if the first letter goes unanswered.
Each morning, before you check your inbox, this reads what came in overnight, sorts it into categories it learned from your last month of mail, drafts replies to anything that asks a direct question, and sends a short briefing of who's waiting and what's due. It never sends or archives anything by itself.
A weekly routine that scans job boards for roles that fit your CV, scores each one, drafts a tailored cover note and a why-me list for the strong matches, and logs everything to a tracker. Built for anyone job hunting who loses hours to the repetitive parts of applying. Nothing gets submitted automatically, you still decide what to send.
Take a photo of your fridge and pantry and get five dinners planned around what you already have, plus a list of what's missing and a Sunday prep order. Built for anyone who opens the fridge most nights with no plan and ends up wasting food or ordering in. It turns one photo into a week of dinners.
You'd share any screenshot, a WhatsApp plan, a poster, an invite, to a shortcut on your phone, and the event would appear on your calendar with the venue mapped, without typing a single field yourself. It would read Chinese and English, work out dates like 'this Friday' relative to today, and only ask you to confirm when it isn't sure.
Turns a textbook chapter into a ready-to-study flashcard deck. Upload or photograph the chapter and it pulls out the definitions, turns diagrams into questions, and flips worked examples around so you solve them yourself instead of reading the solution. Built for students who want a deck without an hour of manual card-making first.
An audit of two creator accounts, post by post, separating pinned and sponsored content from organic performance and sorting the rest by format and hook style, to find which kind of video actually earns views instead of assuming last week's post was a fluke. Built for anyone about to commit to a content plan nobody has checked against the data.
One page that refreshes itself with your day: today's events, unread email that's actually from a person, a daily streak you tap once, and the weather. Built for anyone who checks several apps each morning just to get an overview of their day. It refreshes automatically so it stays current, and restyling it later doesn't touch the data underneath.
A journal that writes itself from the work. Each build session leaves behind the prompts, the decisions and the diff; a small routine turns them into a readable entry for building.rubytang.com and a matching thread for X, so the record of what was built is kept without a separate writing step.
Upload a real estate floor plan and get an interactive 3D model of the flat you can walk through and try furniture in. Built for anyone flat-hunting in a city with small homes, where a queen bed and a desk both fitting matters before signing a lease. It turns a PDF into a space you can test furniture against.
An Instagram account built on Histoline, my live timeline comparing seventeen civilizations side by side. Each post takes one year and splits it in two: what a Chinese dynasty was doing on the left, what the rest of the world was doing on the right. For anyone who likes history but rarely sees it laid out side by side.
Drafts the follow-up message for an unpaid invoice, pitched to how overdue it actually is: a light nudge early on, firmer language after two weeks, and a formal note after a month. Stops drafting the moment the invoice is marked paid. Built for freelancers and small business owners who dread writing the reminder more than they mind sending it.
A tool for anyone who screenshots a health claim from a podcast, article or Instagram caption and wonders if it holds up. It pulls out each claim, finds the actual studies and reviews behind it, and grades the evidence from strong to weak, with every source linked. It never tells you what to do.
Answers a child's "why" question out loud, at a level that actually matches their age, in a few short sentences instead of a lecture, and ends with one question to keep them curious. Built for parents who get a constant stream of these questions and do not always have a patient, accurate answer ready on the spot.
Recommends a film based on what you want it to do for you tonight, not just a favorite genre, learn something, stay motivated, or switch off completely, combined with how you actually feel. Returns three picks with a real reason each one fits both. Built for the ten minutes usually lost scrolling a streaming home screen undecided.
Every link, screenshot and saved post from the week would get pulled together automatically and turned into a short draft newsletter each Sunday: five items, why each one matters, and a short personal take on each. Nothing would send itself; the draft is there to read, edit or throw out, so the only job left is deciding whether to hit send.
A public web page with one text box where anyone could send a short message. Every message would print immediately on a small receipt printer sitting next to my laptop, so the exchange happens in physical form, in real time, in front of whoever is watching, rather than as a comment scrolling past on a screen.
Every Friday, an assistant reads next week's calendar, looks up each external meeting guest, and pulls your last conversation with them, then drops a short prep note for each meeting. Built for anyone who walks into calls without having reread the thread beforehand. It turns fifteen minutes of Sunday-night scrambling into a five-minute Friday read.
A check that would run on every pull request and score it for risk: size, blast radius, and how easy it would be to undo. Low-risk changes would get waved through automatically; risky ones would get flagged for a person, with the reasoning stated in plain language, so review time goes to the changes that actually need a careful look.
Pick a story you already know, a fairy tale, a classic, and hear it retold at your level in the language you are learning. Captions run with the audio and you can tap any word for its meaning without leaving the story. For learners who find graded readers dull and would rather hear a story they already love.
For anyone building in public who doesn't want to get on camera, this turns a week's worth of commits into a 30-second recap video, five short lines of text on screen: what shipped, one real number, the bug that hurt, the lesson, what's next. No filming, no editing software, just the week's own record turned into something postable.
Checks a candidate product name in one place instead of checking five sites separately. Type a name and see whether the matching domains are free and whether the App Store already has something similar, plus direct links to check social handles by hand instead of a fake automated result. Built for anyone naming a new app, account or small product.
A draft-reply tool for the messages sitting in your inbox and team channels waiting on you. It reads what is waiting, drafts a reply, and sends the original message plus the draft to Telegram so you can approve or edit before anything goes out. Built first for my own brand accounts, where I own the data.
Daily five-minute drills on the math people actually use, tips, discounts, compound interest, unit prices, margins, exchange rates, not a school syllabus. For anyone who can do algebra but still pulls out a calculator to check a 15 percent tip. Built like a streak app: short, daily, and it keeps score of what you have gotten fast at.
A daily post about one word whose history would surprise you, which languages it passed through on the way into English and how its meaning drifted along that path. Built for anyone who likes language trivia, and for a small content account that wants a reliable daily post without scrambling for a new topic every morning.
A minimal email client built to replace Gmail's interface: it reads your inbox, sorts threads by what they actually need from you, and writes a draft reply in your own tone that sits in Gmail waiting for a one-tap review. Nothing sends on its own. Built for anyone who spends more time triaging email than answering it.
A weekly digest for anyone running a brand who cannot read every App Store review, support email and social DM as it comes in. It groups what people are actually saying into themes and hands you the three things worth acting on this week, instead of a pile of unread messages spread across four different apps.
Turns a photographed receipt into a clean monthly spending record without opening a spreadsheet by hand. Send a photo and it reads the merchant, date and total into a table, then clears the photo itself after three months so nothing piles up. Built for anyone who tracks spending in bursts of photos and never logs them.
For freelancers who write similar client documents over and over, proposals, intake questionnaires, welcome pages, this drafts each one from a short set of call notes, in a voice trained on real past writing rather than generic copy. Any number it can't find in the notes gets flagged instead of invented. It's a draft to check, not a finished send.
A tutor built from a child's own textbook and homework instead of a generic worksheet. Upload the material and the child's age and it asks questions pitched at that level, gives hints before answers so the child still does the thinking, and sends the parent a short note afterward on what is sticking and what needs more practice.
A vault for warranty cards and receipts you photograph and then forget about. Send in a photo of a purchase and it works out the item, the retailer and how long the warranty runs, then reminds you about a month before it expires, built for anyone who has missed a return or repair window because paperwork got lost.
A watchlist for films that actually tells you when to watch them. Add a title you are waiting on; get a message the day it hits cinemas or streaming where you live, instead of finding out three months late from someone else's post. Each alert comes with three similar titles worth adding while you wait.
For anyone who wants to check on a project without opening a laptop, this is a chat bot that reads files, runs scripts, checks a calendar and takes a screenshot on request, then reports back. Anything that writes, deletes or sends asks for a yes first. Every action is logged, with a switch to turn it off.
An iOS app that reads through years of your own Apple Notes and lets you ask a plain question, like what you decided about a house project, then answers with a link back to the exact note. Built for anyone with thousands of notes who can never find the one that matters.
For product managers whose week lives in scattered docs, chats and meetings, this fills a shared weekly board each morning with goals, decisions due and risks, then writes a short brief in the team's own vocabulary. It watches what gets corrected and suggests one new automation a week. Nothing outside the board it owns gets touched.
Write a product launch video as a short text file describing each scene, and get back a finished 30-second vertical video with no video editor involved. Built for anyone shipping a product solo who needs a launch clip but doesn't want to learn timeline-based editing. Changing the video means editing text and re-rendering, not scrubbing a timeline.
A way to rank a restaurant right after paying, without typing anything. You'd take a photo of the receipt on your way out; the app would read the merchant name and find the matching place, then ask the same three-option question it always asks, loved it, fine, not for me, so the visit gets logged before you're even home.
For anyone doing the small glue work of a job, meeting prep, closing tickets, clearing an inbox, this turns three of those chores into one-line commands. One pulls together attendees and open questions before a meeting, one closes a ticket and tells the team, one drafts replies to emails. The aim is fewer tabs, not a new app.
For engineering teams that start standup by scrolling three separate apps, this drafts the pre-read for you: what shipped, what's stuck in review, what's failing, and what needs a decision, twenty minutes before the meeting starts. It also flags the two updates most likely to need attention. The goal is a shorter meeting, not a longer report.
A language-learning tool for watching a video with the audio swapped into the language you are studying, captions included. Realistically this only works on video where you can actually access the raw audio and text, not major streaming platforms with copy protection, so the honest version targets your own video files, not Netflix or Disney Plus.
A physical button on the desk that approves an AI coding agent's pending action instead of clicking a screen, with a light that turns green when the task finishes. Built for anyone who alt-tabs back to a terminal all day just to type yes, it turns an invisible workflow into something you can film.
Follow a blog you like in a language you are learning, without waiting for someone else to translate it. Each new post arrives translated, side by side with the original, so you read in your target language and check any line against the source. Built for learners who already read blogs, not an app that adds a new habit.