01 · The problem
Boxing apps often push accounts, ads, or cloud sync when fighters mainly need a reliable timer, simple coaching cues, and a private training log.
Gloves Up is a personal boxing training app that keeps workouts, goals, and sparring notes on-device. No signup and no cloud account — built for gyms and home sessions where connectivity is unreliable.
02 · My role
Solo founder · product & engineering (Momentra Labs)
03 · The result
Shipped an Expo React Native app with a round timer, voice coach combos, macros calculator, recovery check-ins, optional training video with on-screen timer, and local history — all offline-first with a clear privacy posture for store listing.
04 · Architecture
- 01
Expo Router client with local AsyncStorage persistence
- 02
On-device repositories for sessions, goals, and journal entries
- 03
Optional camera / mic / gallery permissions for training video only
- 04
No backend; privacy policy hosted on the developer portfolio
Implementation
- Configurable boxing timer with prep, bells, and warning cues
- Coach punch combinations with on-device speech
- Macros calculator and training history
- Optional training video recording with round timer HUD
- Optional local notifications and sparring photo references
- Android APK available to download from this site
Challenges & outcomes
Challenges
- Keeping UX simple for non-technical athletes
- Store-ready privacy and offline data lifecycle without a backend
Outcomes
- Works fully offline after install
- Reset wipes on-device data and returns to welcome flow
Lessons
- Offline-first products need an equally clear privacy story for stores
- Timer and coach cues matter more than dashboards for training focus