Fitness Tracker

A fitness-tracking app that worked fine in the AI tool's preview but crash-looped on a real device — a null-state crash on first launch before onboarding had completed. On top of that, the Firebase security rules were left wide open in test mode, so the entire workout database was world-readable and world-writable. We fixed the null-state crash, wrote real Firebase security rules scoped per-user, and repaired the release build configuration so it could actually be submitted to the app stores. Launch readiness went from 21 to 89 in 29 hours. Beyond the headline fixes, we also cleaned up state management around the onboarding flow so the same class of null-state bug couldn't quietly resurface in a future update, and documented the Firebase rule structure in plain English so future changes don't accidentally reopen the database.