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Watch me build a real app, from idea to launch.
I’m building RepGarden, a web and mobile app for Benji, a personal trainer, and writing up each decision as we make it. If you’re planning an app of your own, the series shows you exactly what the work involves.
The build so far.
- IntroductionWhat we’re buildingMeet Benji and the app we’re building for him and other personal trainers.
- DiscoveryDiscoveryWhy the build starts with two calls and not a prompt: the four parts of a good app, and what AI cannot know about Benji’s clients.
- ResearchResearchFourteen apps trainers already use with their clients, and what they have in common: the features, the marketing, the pricing and the thin game layer.
- Game designGame designOne theme, two places the app gets used, and three things that make rewards mean something. The name RepGarden, and a carrot.
- Game mechanicsGame mechanicsAn old woman who falls ill every Monday, a farm that grows vegetables from logged sets, a week you can share, and the money left undecided on purpose.
- Coming nextMock-ups and user journeysRough mock-ups of the client’s screens and the paths through them, drawn before anything is built. This entry will appear here once there’s something useful to show.
Want your own app built this way? See how a new build works
Articles and guides.
- LaunchMove the paywall earlierI gave new users of my Arabic app three free units before asking them to pay, and trial starts dried up. Moving the paywall to after the first unit brought them back, and the research on when people buy says why.Read
- Coding agentsLevel: TechnicalFive MCP servers that make building mobile apps easierThe five connectors that let a coding agent see the live database, the running app, the subscriptions, the crash reports and the analytics of a mobile app, with how each one earned its place and how to connect it.Read
- DesignColour in apps: two things to avoidForget “avoid purple”. The two habits that make an app’s colours look cheap, and the short checklist that gives you a polished palette without learning colour theory.Read
- ResearchNine gold mines of app researchNine places where the answers about what your users want are already written down, with a real find from each one.Read
- Getting startedHow to build your first app with AIThe whole process of building a mobile app with a coding agent, in order: what to research, what to decide, what to set up, what to build, what to test, and how to get it into the app stores.Read
- Product ideasNot every idea needs an appFive questions that tell you whether your idea needs a mobile app at all, or whether a website, a link or a PDF would serve the people using it better.Read
- DesignYour app’s interface is 10,000 years oldPeople have played and worked in the same few places for as long as there have been people. Design the interface for the room it will be used in, not for the screen.Read
- MarketingCopywriting Is the DifferentiatorThe copywriting rules I keep coming back to: the hook has one job, warm the reader up before you sell, sell the bridge rather than the features, find the moment they start looking, and give AI what only you know.Read
- MarketingSEO Is Not Something You HackYou can research hundreds of keywords, analyse competitors and automate content production, and still get poor results. Here’s what has to come first.Read
- Coding agentsThe Slash Commands I Use in Claude Code and CodexA short cheat sheet of the slash commands I use every day, with the Claude Code and Codex version of each one and a handoff prompt to run before you clear a conversation.Read
- Getting startedDeciding What to BuildFor fun, for money, or to help someone. A few questions worth asking before you give your next big idea months of your life.Read
Want to build your own app?
Getting Started with Coding Agents
Build a small reading-list app with a coding agent, from your first running screen to a link you can share. Decide how the app works and how it looks, guide the agent one piece at a time, and check the result yourself.
No coding experience needed 10 guides
Start the guide