ArenaFit V1
ArenaFit is fitness fused with game design, not bolted on. A two-sided product where athletes earn XP, levels, and rewards for every set, while their coach watches progress in real time and sends programs from the same app. Apple Health and Google Fit integration on day one, RevenueCat subscriptions for both sides, and a working shop economy with progression-unlock and IAP currency paths.
⚙️
Tech Stack
health_kit + health_connect
🧠
Core Technologies
- Flutter 3.x — Single codebase · iOS + Android · 60fps animations
- health_kit + health_connect — Auto-import workouts, sleep, calories, resting HR
- RevenueCat — Two-sided subscriptions · athlete tier + coach tier
- Stripe Connect — Coach payouts · split-payment for subscriptions
- Node + WebSocket — Live leaderboards · real-time client status for coaches
- Redis — Sub-100ms leaderboard ranking · session-scoped caches
📦
V1 Deliverables
✓
Athlete app · sign up + Apple Health / Google Fit sync
V1✓
Goal-pick onboarding + adaptive plan generation
V1✓
Today dashboard · daily challenge banner + metrics grid
V1✓
Active workout · live set tracking (reps/weight/rest timer/XP)
V1✓
Progress charts · lifts vs goal, weekly intensity, achievements
V1✓
The Arena · daily/weekly/monthly challenges + leaderboards
V1✓
Avatar customization + shop (coins/gems · progression + IAP)
V1✓
Coach app · client list, today view, status chips, quick actions
V1✓
Coach tools · send programs, schedule sessions, view client progress
V1✓
Subscription system · RevenueCat both user and coach tiers
V1✓
Push notifications · FCM (challenge ends, coach message, PR)
V1✓
Profile + settings · units, language (FR/EN), notifications
V1→
Live coach 1:1 video sessions (WebRTC)
V2→
AI form-check via on-device camera (MediaPipe)
V2→
Real tournaments + seasonal limited events
V2→
Group leagues · friends-only leaderboards
V2→
Wearable integration · Apple Watch + Wear OS companion apps
V2→
Nutrition tracking + meal plans (synced with calorie targets)
V2→
Mental health · guided breathwork + recovery meditation
V2🏛
Architecture Layers
MOBILE
Flutter · Riverpod · Hive · health_kit · health_connect · biometric_auth
GAME SYSTEMS
XP / level engine · challenge generator · league tiering · avatar inventory · shop economy
API
Node + Express · JWT · OpenAPI · WebSocket (live leaderboards)
DATA
PostgreSQL · Redis (leaderboard cache) · S3 (workout media) · Firestore (chat)
PAYMENTS
RevenueCat (athlete + coach tiers) · Stripe Connect (coach payouts) · IAP (shop currency)
OPS
Fly.io · GitHub Actions · Sentry · PostHog · App Store + Play Store CI