ImuaTrak

Imua — Hawaiian for "charge forward".

Outrigger canoe paddling fitness app for iPhone and Android (with watch support arriving in Phase 2). Records GPS, heart rate, stroke rate, splits, weather, and audio-detected side switches ("huts") for OC1, OC2, OC6, V1, SUP, and surfski sessions. Sessions sync to Firebase, export to Android Health Connect, and export to GPX/FIT for upload to Strava, Garmin Connect, etc.

Stack

• Expo SDK 53 + React Native + TypeScript
• expo-router for file-system routing
• Firebase JS SDK (Auth, Firestore, Storage, Functions)
• expo-location + expo-task-manager for background GPS
• expo-sensors for accelerometer-based stroke detection
• react-native-health + react-native-health-connect for native health stores
• react-native-maps for the route map

Repository layout

app/         expo-router routes (screens)
src/         models, services, hooks, UI components
assets/      icons, splash, fonts
firebase/    Firestore + Storage rules and Cloud Functions
web/         Next.js marketing site + public session viewer (deployed on Vercel)
docs/        Canonical data model and architecture notes

Prerequisites

• Node 20+
• npm i -g eas-cli (cloud builds — needed for iOS until you have a Mac)
• A Firebase project (Auth, Firestore, Storage, Functions enabled)
• For local Android dev: Android Studio + an emulator or a device
• For iOS: a Mac with Xcode 16, or EAS Build (no Mac required)

First-time setup

npm install
cp .env.example .env       # then fill in your Firebase web-app config

For the route map on Android you'll also need a Google Maps SDK for Android API key (from Google Cloud Console → APIs → Credentials). Add it to .env as EXPO_PUBLIC_GOOGLE_MAPS_ANDROID_KEY. iOS uses Apple Maps and doesn't need any key.

Most things you can run today on Android from Linux. Background location, Health Connect, and Sign in with Apple need a development build (not Expo Go):

eas build --profile development --platform android
# install the resulting .apk on your device, then:
npx expo start --dev-client

When the Mac arrives, the same eas build --profile development --platform ios gets you the iOS dev build. No project config changes required.

Watch path

The Apple Watch app lives in targets/watch/ (SwiftUI, standalone GPS + heart rate) and is embedded into every iOS build automatically by @bacons/apple-targets — see targets/watch/README.md for the one-time EAS credentials setup. Finished watch sessions transfer to the phone via WatchConnectivity and sync through the normal pipeline. wear/ holds a Wear OS (Kotlin) skeleton that is not yet buildable or shipped. The phone remains the source of truth. See docs/architecture.md.

Roadmap

• Phase 1 — Phone vertical slice: record, save, sync, export GPX, write to Health.
• Phase 2 — Companion watch apps (Apple Watch + Wear OS).
• Phase 3 — Audio "hut" detection for side switches (custom TF Lite module).
• Phase 4 — Weather capture, social share card, third-party uploaders.
• Phase 5 — Standalone watch apps (record without the phone).