Language Learning App (Lungulu)

A modern, interactive language learning application built with Flutter. This app combines 3D avatars, real-time speech recognition, and gamified progress tracking to provide an immersive learning experience.

📱 Screens & Mockups

Home Dashboard	Conversation Mode	Vocabulary Quiz
Track your progress and weekly activity	Practice speaking with interactive avatars	Master new words with fun quizzes

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✨ Key Features

• 🗣️ Interactive Conversation Practice
  Engage in realistic dialogues with 3D avatars (Clara & Karl). The app uses Speech-to-Text and Text-to-Speech to facilitate two-way communication.

• 🤖 3D Avatar Integration
  Features high-quality 3D avatars that react and animate during lessons.

  • iOS: Native UiKitView integration for USDZ models.
  • Android/Web: model_viewer_plus for seamless 3D rendering.

• 📚 Varied Lesson Types

  • Vocabulary Building: Multiple-choice questions, listening grids, and sentence completion.
  • Listening Comprehension: Audio-based challenges.

• XB Gamified Progress Tracking

  • Radar Charts: Visualize your skills (Listening, Speaking, Vocabulary, Grammar).
  • Weekly Activity: Track the number of words learned each day.
  • Levels & XP: Stay motivated with a progression system.

• 🎨 Modern UI/UX

  • Clean, colorful interface with smooth animations (Lottie).
  • Responsive layout adapted for various screen sizes.

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🛠️ Tech Stack

• Framework: Flutter (Dart)
• State Management: Provider
• Architecture: Feature-first / Clean Architecture

Key Packages & Libraries

| Package | Purpose | |pV |pV | | provider | State Management (ChangeNotifier) | | speech_to_text | Real-time speech recognition | | flutter_tts | Text-to-Speech synthesis | | model_viewer_plus | 3D Model rendering (Web/Android) | | fl_chart | Data visualization (Radar & Bar charts) | | lottie | High-quality animations | | http | API communication (Ready for backend integration) | | shared_preferences | Local data persistence | | webview_flutter | Web content rendering |

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📂 Project Structure

The project follows a Feature-First directory structure for better scalability and maintainability.

lib/
├── app/                  # App-wide configurations (Theme, Router, Constants)
├── core/                 # Shared utilities, widgets, and data layer
│   ├── data/             # Repositories (Mock & Real)
│   ├── models/           # Data models (JSON serialization)
│   ├── providers/        # Global providers (Auth, Theme, etc.)
│   └── services/         # External services (Audio, API clients)
├── features/             # Feature-specific modules
│   ├── auth/             # Authentication screens & logic
│   ├── avatar/           # 3D Avatar controllers & views
│   ├── home/             # Dashboard & main navigation
│   ├── conversation/     # Chat & Speech logic
│   ├── vocabulary/       # Quiz & Learning logic
│   └── onboarding/       # Intro screens
└── main.dart             # Entry point & MultiProvider setup

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🚀 Getting Started

Prerequisites

• Flutter SDK (Version >= 3.0.0 recommended)
• Android Studio / VS Code with Flutter extensions
• iOS Simulator (Mac only) or Android Emulator

Installation

1. Clone the repository:

   git clone https://github.com/your-username/language-learning-app.git
   cd language-learning-app

2. Install dependencies:

   flutter pub get

3. Run the app:

   flutter run

⚠️ Note on 3D Avatars (iOS vs Android)

• Android: Uses model_viewer_plus which loads GLB/GLTF models.
• iOS: Uses native UiKitView. Ensure your ios/Runner/Info.plist has the necessary permissions for camera/microphone if AR features are enabled.

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🧪 Testing

Run unit and widget tests:

flutter test

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🤝 Contributing

Contributions are welcome! Please follow these steps:

1. Fork the project.
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.

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📄 License

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