Familiar calculator-style budget tracking app for Android.
Built with Jetpack Compose and Material Design 3 Expressive
- Easy Expense Entry: Log expenses directly through a Numpad interface.
- Splitting Functionality: Built-in functionality to split checks among multiple people directly on demand.
- CSV Export: Securely export expense data to the device Downloads folder for backup or further analysis in spreadsheet software.
- Undo & Batch Actions: Restore individual expenses or delete all at once.
- Wear OS Integration: Provides a companion app for quick expense entry on wearable devices.
- Subscription Management: Easily manage and track subscriptions.
- Material Design 3: Dynamic colors, smooth animations, predictive back gestures.
- Customizable Settings: Light/Dark/System themes, Material You colors.
The primary goal of Minus is to provide a "zero-friction" interface for recording daily spending. By mimicking the layout of a standard calculator interface that reduces it's complexity, that way any user can easy and quickly enter their expenses.
| Category | Technology | Purpose |
|---|---|---|
| UI Framework | Jetpack Compose | Declarative UI for Mobile and Wear OS |
| Architecture | MVI (Model-View-Intent) | Uni-directional data flow and state management |
| Asynchronous / Streams | Kotlin Coroutines & Flow | Non-blocking database I/O and reactive state updates |
| Dependency Injection | Hilt / Dagger | Modular dependency management and scoping |
| Database | Room | Local persistence with SQLite |
| Logging | Logcat (Square) | Pattern-based structured logging |
| Navigation | Compose Navigation | Type-safe in-app navigation |
| Design System | Material 3 Expressive (Alpha) | Modern UI components and dynamic theming |
- Calculator-First Entry: Log expenses directly through a Numpad interface.
- Check Splitting: Built-in functionality to split checks among multiple people directly on demand.
- CSV Export: Securely export expense data to the device Downloads folder for backup or further analysis in spreadsheet software.
Minus follows Modern Android Development (MAD) practices and a Clean Architecture approach:
- Presentation Layer: Built entirely with Jetpack Compose. Uses ViewModel and StateFlow for reactive UI updates.
- Data Layer: Utilizes Room Database for local persistence and MediaStore for file exports.
- Navigation: Managed via Jetpack Compose Navigation with a centralized AppNavGraph.
- Concurrency: Powered by Kotlin Coroutines and Flow for non-blocking operations.
- Wear OS Integration: Provides a companion app for quick expense entry on wearable devices.
- MVI (Model-View-Intent) Architecture: Used for state management and event handling.
- Numpad: A highly optimized custom grid layout using weight-based animations for mode transitions.
- NumpadButton: Custom buttons with smooth, state-aware corner radius transitions (Circle to Rounded Square).
- WavyDivider: A custom drawing component that uses BoxWithConstraints to ensure consistent rendering across different aspect ratios and accessibility settings.
Minus includes a companion Wear OS application. The wearable version provides:
- Quick-add functionality for common expense amounts.
- Glanceable history of recent entries.
- Optimization for round and square watch faces using the latest Wear OS Compose libraries.