Fitor4Fit
Overview
A fitness accountability app built entirely using Claude Code. Users commit to fitness goals with real stakes, If you hit your target, you win; if you don't, you pay.
Technical Details
- Built end-to-end with Claude Code as an experiment in AI-assisted development
- React Native front-end for iOS and Android
- Mileage only workouts tracked via HealthKit integration
- Payments handled with Stripe and Payouts with PayPal/Venmo
- Backend built with Supabase for authentication, database, and serverless functions
- Currently in development
Motivation
I wanted to see how far I could push Claude Code in building a real, usable app and I'd been planning this fitness accountability app for a while. It seemed like a perfect fit for an AI-assisted development experiment. The app itself is pretty simple, but there are some tricky parts around the payments and processing a possibly large number of user's every week. I wanted to see if Claude could handle those complexities and if the resulting code would be secure and reliable enough for a real app with real users.
Results
We'll see. The app is still in development, but I'm starting to feel confident in the code that Claude writes, or at least in my ability to test that code. I've build a number of e2e tests that stress the challenge processing and payment flows with 10s of 1000s of users. I go into more detail on my processes around testing and validating Claude's code in this blog post.