Motion-fits

What it is

Most fitness apps are a social network with a workout attached, or a spreadsheet with bad typography. This one is the opposite: a fast, private, single-user tracker that opens instantly, logs a session in under ten seconds and never asks for an account.

No backend and no login, so every byte lives on the device. That removed auth, sync and a privacy surface, and made the app genuinely fast.

What got cut

The screen set stays small on purpose: a home dashboard with today's ring, a quick-log flow, history and settings. Each interaction had to be reachable with a thumb while walking.

React Native with Expo Router gives file-based navigation on Android, so the route tree mirrors the folder tree and deep links come nearly free. A single store plus selectors covers state without a heavy library. Persistence is local and write-through, so closing the app mid-session never loses a set. Charts use lightweight primitives instead of a charting library, which keeps the bundle small and the render path predictable on older devices.

The first draft had six screens and a social feed. Deleting the feed doubled the quality of the four screens that remained. The Android build runs in a Pixel 7 emulator through Appetize, so the actual APK can be tested in a browser without installing anything.