Flashcard 📚

A modern Android flashcard application designed to help you learn and retain information effectively using spaced repetition techniques.

Features ✨

• Smart Flashcards: Create and manage flashcards organized by categories
• Spaced Repetition: Cards are reviewed based on your performance (Bad, OK, Good ratings)
• Progress Tracking: Monitor your learning with detailed statistics and charts
• Streak Counter: Stay motivated with daily streak tracking
• Cloud Backup: Sync your flashcards across devices using Firebase Storage
• Google Sign-In: Secure authentication with your Google account
• Offline Support: Study your cards even without internet connection using local Room database
• Beautiful UI: Clean, intuitive interface with smooth animations

Screenshots 📱

Coming soon

Tech Stack 🛠️

• Language: Kotlin
• Architecture: Android Activity-based architecture
• Local Database: Room (SQLite)
• Cloud Storage: Firebase Storage
• Authentication: Google Sign-In
• Charts: MPAndroidChart
• Image Loading: Glide
• JSON Parsing: Gson
• Minimum SDK: 28 (Android 9.0)
• Target SDK: 35

Prerequisites 📋

Before you begin, ensure you have the following installed:

• Android Studio (Latest stable version recommended)
• JDK 8 or higher
• Android SDK with API level 28 or higher
• A Firebase project (for cloud backup functionality)

Getting Started 🚀

1. Clone the repository

git clone https://github.com/a-y-a-n-das/flashcard.git
cd flashcard

2. Firebase Setup

1. Go to the Firebase Console
2. Create a new project or use an existing one
3. Add an Android app with package name com.example.flashcard
4. Download the google-services.json file
5. Place it in the app/ directory (already included in this repo)
6. Enable Firebase Storage in your Firebase project
7. Enable Google Sign-In in Authentication settings

3. Build and Run

Open the project in Android Studio and let it sync the Gradle files. Then:

./gradlew assembleDebug

Or simply click the Run button in Android Studio.

Project Structure 📁

flashcard/
├── app/
│   ├── src/
│   │   ├── main/
│   │   │   ├── java/com/example/flashcard/
│   │   │   │   ├── MainActivity.kt          # Home screen with categories
│   │   │   │   ├── Card.kt                  # Flashcard review activity
│   │   │   │   ├── Stats.kt                 # Statistics and profile screen
│   │   │   │   ├── CategoriesActivity.kt    # Category management
│   │   │   │   ├── addCard.kt               # Add new flashcard
│   │   │   │   ├── ViewCategory.kt          # View cards in category
│   │   │   │   ├── SignInActivity.kt        # Google Sign-In
│   │   │   │   ├── AppDatabase.kt           # Room database configuration
│   │   │   │   ├── CardDao.kt               # Card data access object
│   │   │   │   ├── CategoryDao.kt           # Category data access object
│   │   │   │   ├── CardDataClass.kt         # Data models
│   │   │   │   ├── BackupManager.kt         # Firebase backup/restore
│   │   │   │   └── UsageTracker.kt          # Time tracking
│   │   │   └── res/                         # Resources (layouts, drawables, etc.)
│   │   ├── androidTest/                     # Instrumentation tests
│   │   └── test/                            # Unit tests
│   └── build.gradle.kts                     # App-level build configuration
├── build.gradle.kts                         # Project-level build configuration
├── settings.gradle.kts                      # Gradle settings
└── gradle/                                  # Gradle wrapper files

How It Works 🎯

Spaced Repetition Algorithm

The app uses a simple but effective spaced repetition system:

1. New cards are shown immediately
2. After reviewing a card, rate your recall:
   • Bad (0): Card will be shown again soon
   • OK (1): Card will be shown in moderate intervals
   • Good (2): Card will be shown less frequently
3. Cards are filtered based on score and last review date to optimize learning

Data Persistence

• Local: Room database stores all flashcards, categories, and progress locally
• Cloud: Firebase Storage backs up your data for cross-device sync
• Offline-first: The app works offline and syncs when connectivity is available

Dependencies 📦

Library	Purpose
Room	Local SQLite database
Firebase Storage	Cloud backup
Firebase Analytics	Usage analytics
Google Play Services Auth	Google Sign-In
MPAndroidChart	Statistics visualization
Glide	Image loading and caching
Gson	JSON serialization

Contributing 🤝

Contributions are welcome! Please feel free to submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

License 📄

This project is licensed under the MIT License - see the LICENSE file for details.

Author 👨‍💻

Ayan Das

• GitHub: @a-y-a-n-das

Acknowledgments 🙏

• MPAndroidChart for beautiful charts
• Glide for efficient image loading
• Firebase team for excellent backend services

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