FlexTrack is a mobile fitness tracking application that helps you plan, execute, and analyse your training. It includes a full active-workout experience with per-set logging and a rich stats dashboard — all stored locally on device with no account required.
| Today | Workouts | Active Workout | Workout Summary |
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| Template Editor | History | Training Progress | Body Metrics |
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The screenshots use a 430 × 932 mobile viewport and are stored at 3× resolution (1290 × 2796). They use deterministic local demo data against the current web app.
- Highlights a routine scheduled for today with one-tap start
- Shows sessions completed this week and total workout count
- Displays the seven-day routine schedule and quick access to the first three routines
- Create, edit, search, start, and delete reusable routines
- Mix repetition, timed, and distance exercises in one routine
- Configure sets, reps, weight or assistance, duration, distance units, rest time, and weekly schedule
- Support weighted, bodyweight, and assisted repetition exercises
- Log every set with weight, reps, duration, or distance as appropriate
- Compare a set with values from the previous matching session
- Mark sets individually or complete all sets in an exercise
- Update an exercise's default weight during a session
- Use the built-in plate calculator for externally loaded exercises
- Run per-set timers and an adjustable rest countdown with vibration feedback
- Keep the screen awake and guard against accidentally leaving a session
- Review duration, completed exercises, sets, volume, and per-exercise results after saving
- Record an activity that was completed outside a routine
- Supports strength, run, walk, cycle, timed, and other activities
- Captures completion time, duration, distance and unit when relevant, plus notes
- Adds the activity directly to History and Progress
- Browse a tappable 28-day activity grid
- See total workouts, average duration, and current streak
- Filter by routine or a selected day
- Review sessions grouped by month with duration, volume, and exercise details
- Derives personal records from the exercise data actually logged
- Shows a 14-day consistency chart and Push / Pull / Legs / Cardio training split
- Charts the last eight progression points for a selected exercise
- Chooses metrics for each modality, including weight, estimated 1RM, reps, assistance, duration, distance, and pace
- Logs height and body weight, calculates BMI, and charts the five latest weight entries
- Bottom tabs for Today, Workouts, History, and Progress
- Central Quick Start sheet for launching routines, logging completed activity, or creating a routine
- Haptic feedback for navigation, workout starts, and completed sets on supported devices
- Focused full-screen layouts for routine editing, active workouts, summaries, and Quick Log
| Layer | Technology |
|---|---|
| Framework | React Native 0.81 + Expo 54 |
| UI library | React 19 |
| Language | TypeScript 5.9 |
| Web bundler | Vite 6 + react-native-web |
| Navigation | Manual view-state (useState) in App.tsx |
| Persistence | @react-native-async-storage/async-storage |
| Charts | react-native-chart-kit + react-native-svg |
| Date utilities | date-fns |
| Icons | lucide-react-native |
| Haptics | expo-haptics |
| Gradients | expo-linear-gradient |
| Screen awake | expo-keep-awake |
| Architecture | React Native New Architecture (enabled) |
| Compiler | React Compiler (experimental, enabled) |
flex-track/
├── App.tsx # Root view-state router and data wiring
├── constants/
│ └── theme.ts # Shared colors, type, spacing, and shadows
├── types/
│ └── index.ts # Templates, exercises, logs, profile, and views
├── hooks/
│ ├── useWorkoutDataSafe.ts # Validated, serialized AsyncStorage operations
│ └── useWorkoutTimer.ts # Exercise timers and rest countdown
├── utils/
│ ├── progress.ts # Modality-aware progress calculations
│ ├── time.ts # Duration parsing and formatting
│ ├── formatters.ts # Schedule labels
│ └── helpers.ts # ID generation
├── components/
│ ├── layout/ # Header and bottom navigation
│ └── ui/ # Buttons, cards, chips, and empty states
└── pages/
├── Dashboard/ # Today, schedule, and routine shortcuts
├── Templates/ # Routine list and editor
├── ActiveWorkout/ # Guided session, set logging, rest, and summary
├── QuickLog/ # Completed-activity entry
├── History/ # Activity grid, filters, and workout cards
└── Stats/ # Training progress and body metrics
WorkoutTemplate {
id, name, description?,
exercises: Exercise[],
tags?: string[],
scheduleDays?: number[] // 0 = Sun … 6 = Sat
}
Exercise {
id, name,
type: 'reps' | 'timer' | 'distance',
loadMode?: 'external' | 'bodyweight' | 'assisted',
targetSets?, targetReps?, targetWeight?,
targetDurationSeconds?, targetDistance?, targetDistanceUnit?,
restSeconds?, notes?
}
WorkoutLog {
id, templateId?, templateName,
source?: 'routine' | 'quick',
activityCategory?: 'strength' | 'run' | 'walk' | 'cycle' | 'timed' | 'other',
notes?,
startTime: number, // Unix ms
endTime?: number,
exercises: ExerciseLog[]
}
ExerciseLog {
exerciseId, exerciseName,
exerciseType?, loadMode?, distanceUnit?,
sets: SetLog[],
completed: boolean
}
SetLog {
setNumber, reps?, weight?,
distance?, durationSeconds?,
completed: boolean, notes?
}
UserProfile {
height?: number, // centimetres
weightLogs: { date: number, weight: number }[] // kilograms
}# Clone the repository
git clone https://github.com/HatefulRock/FlexTrack.git
cd flextrack/flex-track
# Install dependencies
npm installWeb (Vite — recommended for development):
npm run devOpen http://localhost:3000 in your browser.
Mobile (Expo):
npx expo startThen:
- Physical device: Scan the QR code with the Expo Go app
- iOS Simulator: Press
i - Android Emulator: Press
a
Web:
npm run build # outputs to dist/
npm run preview # preview the production build locallyMobile (via EAS):
# Install EAS CLI
npm install -g eas-cli
# Log in to Expo
eas login
# Build for Android (APK)
eas build --platform android --profile preview
# Build for iOS (requires Apple Developer account)
eas build --platform iosConfiguration is in eas.json.
State management is intentionally simple: local React state in App.tsx drives the current screen and active session. There is no Redux, Zustand, or application context.
Persistence is handled by useWorkoutDataSafe, which validates and bounds stored values and serializes writes to the three AsyncStorage keys: workout-templates, workout-logs, and user-profile. No sync layer or remote database is involved.
Performance — expensive derivations are memoized, and the chart-heavy Stats screen is loaded only when opened.
- Data is local to the current browser or device; there is no account, cloud sync, or remote database.
- The included AI Creator screen is an unlinked coming-soon prototype. No AI provider or API key is configured, and the current product does not generate routines with AI.
- Exercise grouping for the training split is inferred from exercise names.
- Fork the repository
- Create a feature branch:
git checkout -b feature/my-feature - Commit your changes:
git commit -m "feat: add my feature" - Push to the branch:
git push origin feature/my-feature - Open a Pull Request
This project is licensed under the MIT License.
Built with React Native · Expo · TypeScript