Coina - Cryptocurrency Mobile App

A modern cryptocurrency mobile application built with Kotlin Multiplatform Mobile (KMM) for Android and iOS platforms.

📱 Screenshots

Android	iOS

🚀 Description

Coina is a comprehensive cryptocurrency mobile application built using Kotlin Multiplatform Mobile (KMM) technology. The app provides real-time cryptocurrency information, market data, and portfolio tracking across both Android and iOS platforms with a shared codebase.

Key Features

• Cross-Platform: Single codebase for Android and iOS
• Real-time Data: Live cryptocurrency prices and market information
• Modern UI: Material Design 3 on Android, SwiftUI on iOS
• Offline Support: Local data storage with Realm database
• Dark/Light Theme: Adaptive theming support
• Modular Architecture: Clean separation of concerns with feature modules

Data Source

Powered by the free CoinGecko API for real-time cryptocurrency data.

🏗️ Architecture

Shared Module

The core of the application is built around a shared Kotlin module that contains:

• Database Layer: Realm database for local data persistence
• API Layer: HTTP client with Ktor for network requests
• Storage Layer: Cross-platform key-value storage (SharedPreferences/UserDefaults)
• Business Logic: Use cases and view models shared between platforms
• Data Models: Common data structures and serialization

Platform-Specific Modules

Android Features

• androidFeatures:core - Core Android utilities and base classes
• androidFeatures:auth - Authentication screens and logic
• androidFeatures:home - Home screen and main navigation
• androidFeatures:coin - Cryptocurrency details and charts

📱 Application Features

Core Screens

1. Authentication Screen - User login and session management
2. Home Dashboard - Market overview and trending cryptocurrencies
3. Cryptocurrency List - Comprehensive list of all available coins
4. Exchange List - Cryptocurrency exchange information
5. Categories - Cryptocurrency categories and classifications
6. Category Coins - Coins filtered by specific categories
7. Coin Details - Detailed information, charts, and market data

🛠️ Technology Stack

Shared Module

• Ktor Client - HTTP networking and API communication
• Realm Kotlin SDK - Local database and data persistence
• Kotlinx Serialization - JSON serialization/deserialization
• Kotlin Coroutines - Asynchronous programming
• CocoaPods - iOS dependency management

Android Platform

• Jetpack Compose - Modern declarative UI toolkit
• Material Design 3 - Latest Material Design components
• Hilt - Dependency injection framework
• Navigation Compose - Type-safe navigation
• Coil - Image loading and caching
• Firebase - Analytics, Crashlytics, and cloud services
• MPAndroidChart - Interactive charts and graphs
• Timber - Logging framework
• MultiDex - Support for large applications

iOS Platform

• SwiftUI - Declarative UI framework
• Material Components - Google's Material Design for iOS
• ObjectMapper - JSON object mapping
• CocoaPods - Dependency management
• Ktor Darwin Client - iOS-specific HTTP client

🎯 Learning Objectives

This project demonstrates several key concepts in mobile development:

1. Cross-Platform Data Storage - Shared key-value storage using SharedPreferences (Android) and UserDefaults (iOS)
2. Shared ViewModels - Business logic sharing between platforms with common state management
3. Database Integration - Realm database queries and local data persistence
4. Navigation Patterns - Platform-specific navigation implementations
5. Theme Support - Dark and light mode implementation across platforms
6. Modular Architecture - CocoaPods integration for shared library management

📊 Application Flow

User Journey

Feature Architecture

📸 Media Resources

• Screenshots: View all application screenshots
• Demo Video: Platform comparison video

💻 Development Requirements

IDE Requirements

• Android Studio: Flamingo | 2022.2.1 Canary 5 or later
• Xcode: Version 14.2 (14C18) or later
• Kotlin: 1.6.20
• Gradle: 8.0.0-alpha05

System Requirements

• Android: API 24+ (Android 7.0)
• iOS: 14.1+
• macOS: Required for iOS development

🚀 Getting Started

Prerequisites

1. Install Android Studio with latest SDK
2. Install Xcode (macOS only)
3. Install CocoaPods: sudo gem install cocoapods

Setup Instructions

1. Clone the Repository

git clone https://github.com/0x0zeus/coina-cryptocurrency-app.git
cd coina-cryptocurrency-app

2. Android Setup

# Open in Android Studio
# Sync project with Gradle files
# Install dependencies automatically

3. iOS Setup

cd iosApp
pod install
cd ..

4. Run the Applications

Android:

• Open project in Android Studio
• Select target device/emulator
• Click Run button

iOS:

• Open iosApp/iosApp.xcworkspace in Xcode
• Select target device/simulator
• Click Run button

Troubleshooting

If you encounter build issues:

# Clean and rebuild
cd iosApp
pod update shared
pod install
cd ..
# Clean Android project in Android Studio

📚 Learning Resources

Kotlin Multiplatform Mobile

• KMM Official Documentation
• Ktor Multiplatform Client
• Shared ViewModels Architecture
• KMM Shared ViewModels

Data Storage & APIs

• Shared Preferences in KMM
• CoinGecko API Documentation
• Realm Kotlin SDK

UI Development

• SwiftUI Tutorials
• MPAndroidChart Library
• Xcode Kotlin Plugin

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request. For major changes, please open an issue first to discuss what you would like to change.

📄 License

This project is licensed under the Apache License 2.0 - see the LICENSE file for details.

👨‍💻 Author

Haruki Mizuno

• GitHub: @0x0Zeus

🙏 Acknowledgments

• CoinGecko for providing the free cryptocurrency API
• JetBrains for Kotlin Multiplatform Mobile
• Google for Material Design and Android tools
• Apple for SwiftUI and iOS development tools