A personal Android gym tracking app built with Kotlin and Jetpack Compose. Inspired by Obsidian, all data is stored as plain .md files with YAML frontmatter — no database, no cloud, full ownership of your data.
Main screen (gitgraph) | Active routine | Exercise editor
- Gitgraph dashboard — 4×7 grid of the last 28 days. Each cell shows a workout's tonnage change vs. the previous session for that routine (green = improved, red = regressed). Routine names appear below the current week.
- Week view — see which routines are assigned to each day of the week.
- Exercise library — exercises grouped by body part with orange (strength) / blue (stretch) color coding. Attach an image or YouTube link to any exercise.
- Routine builder — configure sets, rep ranges, and pair exercises into supersets with a chain-link button. Drag-and-drop reorder.
- Active workout — tap an exercise to log sets. Strength exercises use a vertical scroll picker (no keyboard). Stretch exercises use a stopwatch with a status-bar notification.
- Supersets — interleaved sets for two paired exercises in a single screen, pre-populated from your previous session.
- Progress charts — per-bodypart tonnage line chart after completing a routine. Compares only exercises present in both sessions for a fair comparison.
- Auto-save — all text fields save automatically with a 500 ms debounce. No save button.
- File-based storage — data lives in
gymdata/inside app internal storage as plain Markdown files. Easy to inspect, back up, or migrate.
| Layer | Technology |
|---|---|
| Language | Kotlin |
| UI | Jetpack Compose + Material3 (dark only) |
| DI | Hilt |
| Navigation | Compose Navigation |
| YAML parsing | snakeyaml-engine |
| Image loading | Coil |
| Charts | Custom Canvas (TonnageLineChart) |
app/src/main/java/…/
├── data/
│ ├── model/ # Exercise, Routine, WorkoutSession, ExerciseSet
│ ├── parser/ # Markdown+YAML serialization
│ ├── repository/ # File-based CRUD with in-memory cache
│ └── util/ # StringUtils (slugify), DataChangedSignal
├── di/ # Hilt modules
├── ui/
│ ├── components/ # Reusable composables (ScrollPickerInput, MediaPreview, …)
│ ├── navigation/ # AppNavigation, Screen routes
│ ├── screen/ # One package per screen (Screen + ViewModel)
│ └── theme/ # Dark Material3 theme
└── service/ # StopwatchService (foreground)
gymdata/
├── exercises/ # {slug}-{ex-id}.md
├── routines/ # {slug}-{rt-id}.md
├── history/
│ ├── YYYY/MM/ # YYYY-MM-DD_{routineId}_{sessionId}.md
│ └── _idx/ # {exerciseId}.idx (exercise → session path index)
└── image_cache/ # Coil permanent disk cache
# Debug APK
ANDROID_HOME=~/Android/Sdk ./gradlew assembleDebug
# Install on connected device / emulator
ANDROID_HOME=~/Android/Sdk ./gradlew installDebugRequires Android SDK with min API 26 (Android 8.0).
Wireframes and functional specs are in the Design/ folder (Excalidraw files).
Personal project — all rights reserved.