Burn Tracker
An offline workout, step and calorie tracker. No account, no ads, no internet — your data never leaves your phone.
Log every set you lift, your daily steps and your body weight, and see how many calories you actually burned each day — resting, walking and lifting combined.
Android will warn that the app comes from an unknown developer. That's because it isn't on the Play Store yet — tap More details → Install anyway.
Features
Workout logging
- Exercises grouped by body part (Chest, Back, Legs, Shoulders, Arms, Core, Cardio) — ~80 built in, plus your own
- Every set logged individually: weight, reps and the rest you actually took
- "Last time" hint and your personal record when you open an exercise, so you know what to beat
- 🏆 New-PR celebration when you lift more than ever before
- Tap any logged exercise to edit it; deleting has an Undo
- Rest timer that records real rest time, with +15s / +30s adjustments
- Lock-screen controls (Android): finish a set, start the next one and get an alarm when rest is over — without unlocking the phone
Calories
- Resting burn from the Mifflin-St Jeor equation
- Lifting burn from MET values plus the mechanical work of moving the weight (heavier = more calories)
- Walking burn from steps, using your height for stride length
- Optional "calories eaten" to see your daily surplus or deficit
Progress & history
- Daily step and active-calorie goals with progress rings, streaks and celebrations
- Weekly weigh-ins with a trend chart and goal-weight progress
- Custom goals for anything ("Bench 100 kg", "Run 5 km", "Water 3 L")
- Calendar view — coloured dots show which body parts you trained each day; tap a day for full details
- Weekly balance ("Chest 2×, Legs 1×, Back 0× — last trained 9 days ago")
- Per-exercise progress charts: top weight, estimated 1RM and volume over time
- Planned rest days that keep your streak alive, and a nudge if you forgot yesterday's steps
Everything else
- Light / dark / system theme
- Backup & restore as a single file (save it to Google Drive, iCloud, anywhere)
- CSV export of every set for Google Sheets / Excel
- 100% offline — the app has no server and sends nothing anywhere
How calories are estimated
| Part | Formula |
|---|
| Resting (BMR) | Mifflin-St Jeor: 10·kg + 6.25·cm − 5·age (+5 male / −161 female) |
| Strength | (MET − 1) · kg · hours for the set-and-rest period + load · g · range-of-motion · reps ÷ 4184 ÷ 20 % efficiency |
| Cardio | (MET − 1) · kg · hours |
| Walking | 0.5 kcal · kg · km, stride ≈ 0.415 · height |
MET values come from the Compendium of Physical Activities. These are estimates — useful for trends, not lab-grade.
Tech
- Expo SDK 57 / React Native / TypeScript
AsyncStorage for all data (on-device only)expo-notifications + expo-task-manager for lock-screen controlsexpo-sensors pedometer for live step countingreact-native-svg for charts and progress rings- Web build is a PWA (manifest + service worker) deployed to GitHub Pages by GitHub Actions on every push
Project structure
App.tsx tabs, startup, notification wiring
src/
calc.ts calorie maths
exercises.ts exercise library + user-added exercises
storage.ts everything saved on the device
workout.ts in-progress workout, rest timer, lock-screen notifications
backup.ts backup / restore / CSV export
theme.tsx, ui.tsx colours, dark mode, shared components
screens/ Today, Log (+ ExercisePicker), Progress, History, Profile
scripts/build-web.mjs builds the installable web version
.github/workflows/ deploys the web app to GitHub Pages
Run it yourself
npm install
npx expo start # scan the QR code with Expo Go (lock-screen buttons need a real build)
Build an Android APK in the cloud (free Expo account):
npx eas-cli@latest build -p android --profile preview
Build the web version:
# PowerShell: $env:WEB_BASE_URL='/burn-tracker'; node scripts/build-web.mjs
WEB_BASE_URL=/burn-tracker node scripts/build-web.mjs
Privacy
There is no server, no analytics and no account. All data is stored on your device and only leaves it when you tap Backup or Export. The Android build requests two permissions: Physical activity (step counting) and Notifications (rest timer).
Roadmap / ideas
- Health Connect / Apple Health sync for automatic step counts
- Google Play release
Built for fun by Rushikesh Ware.
