🛡️ Valguard

A modern cryptocurrency portfolio tracker built with Kotlin Multiplatform

Valguard is a production-ready cryptocurrency portfolio tracking application that demonstrates modern mobile development practices with Kotlin Multiplatform and Compose. Track your crypto holdings, monitor real-time prices, and manage your investment strategy—all with a premium dark UI.

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✨ Features

• 📊 Real-time Price Tracking - Live cryptocurrency prices via WebSocket (CoinCap)
• 💼 Portfolio Management - Track holdings, value, and performance
• ⭐ Watchlist - Save favorite coins for quick access
• 📈 Price Charts - Historical price data with multiple timeframes
• 💰 Simulated Trading - Practice buying/selling without real money
• 🔔 DCA Scheduling - Set up recurring buy reminders
• 🔍 Coin Comparison - Side-by-side analysis of cryptocurrencies
• 🌙 Dark Theme - Premium gradient design with smooth animations
• 📴 Offline Support - Cached data available without internet

⚠️ Educational Purpose: This app uses simulated trading only. No real cryptocurrency transactions occur. No exchange integration, KYC, or compliance features.

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🏗️ Architecture

Tech Stack:

• Kotlin Multiplatform - Share business logic across platforms
• Compose Multiplatform - Unified UI framework
• MVVM + Clean Architecture - Scalable, testable code structure
• Room Database - Local data persistence with migrations
• Ktor - HTTP client and WebSocket support
• Koin - Dependency injection
• Coroutines & Flow - Asynchronous programming
• Kotest - Property-based testing

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🔐 Security & Production Readiness

✅ Security Hardened:

• Cleartext traffic disabled (HTTPS/WSS only)
• ProGuard/R8 enabled for code obfuscation
• No hardcoded credentials or API keys
• Secure local storage with Room encryption

✅ Production Features:

• Proper database migrations (no data loss)
• Error handling with user-friendly messages
• Offline-first architecture
• Memory leak prevention
• Optimized APK size (~15-20 MB)

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📊 Data Source

This project uses real market data from CoinGecko API with a cache-first architecture:

• 🌐 API: CoinGecko public API (free tier)
• 💾 Caching: Room database with 5-minute staleness threshold
• 🔄 Real-time: CoinCap WebSocket for live price updates
• 📴 Offline: Full functionality with cached data

Data Flow:

CoinGecko API → Room Cache → Repository → ViewModel → UI
     ↓                                                  ↑
Real-time WebSocket ──────────────────────────────────┘

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🚀 Getting Started

Prerequisites

• Android Studio Hedgehog or later
• JDK 11 or later
• For iOS development: Xcode 15+ and macOS

Project Structure

• /composeApp - Shared code for both platforms

  • commonMain - Platform-agnostic code
  • androidMain - Android-specific code
  • iosMain - iOS-specific code

• /iosApp - iOS app entry point

Build and Run Android

From Android Studio:

• Use the run configuration from the toolbar

From Terminal:

# macOS/Linux
./gradlew :composeApp:assembleDebug

# Windows
.\gradlew.bat :composeApp:assembleDebug

Build and Run iOS

From Xcode:

• Open /iosApp directory in Xcode
• Select target device/simulator
• Press Run (⌘R)

From Android Studio:

• Use the iOS run configuration from the toolbar

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📱 Screens & Features

Main Screen

• Market Tab - Browse all available cryptocurrencies
• Portfolio Tab - View holdings and total value
• Watchlist Tab - Quick access to favorite coins

Coin Detail

• Live price with 24h change
• Interactive price chart (1H, 24H, 7D, 1M, 1Y)
• Market statistics (Cap, Volume, Supply, ATH/ATL)
• Holdings display (if owned)
• Buy/Sell actions

DCA (Dollar-Cost Averaging)

• Create recurring buy schedules
• Multiple frequencies (Daily, Weekly, Biweekly, Monthly)
• Schedule management (pause/resume/delete)
• Execution history tracking

Compare

• Side-by-side coin comparison
• Metric-by-metric analysis
• Save comparisons for later
• Winner highlighting

Additional

• Referral System (UI ready)
• Leaderboard (Performance rankings)
• Price Alerts (UI ready)

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📚 Documentation

• VALGUARD_APP.md - Complete application documentation
• SECURITY_FIXES_APPLIED.md - Security improvements
• DATABASE_MIGRATIONS.md - Migration guide
• VERIFICATION_REPORT.md - CoinGecko integration verification
• REALITY_TESTING_GUIDE.md - Testing procedures

Technical Fix Reports

• Portfolio 24h Change Fix
• Chart Race Condition Fix
• Coin Icon Standardization
• Portfolio Price Sync Fix

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🧪 Testing

Unit Tests

# Run all tests
./gradlew test

# Run specific module tests
./gradlew :composeApp:testDebugUnitTest

Property-Based Testing

• Uses Kotest for robust testing
• Validates UI components across all screen sizes
• Tests data flow integrity

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🔧 Configuration

API Keys

No API keys required! Uses CoinGecko's public API (free tier).

ProGuard Rules

Release builds use comprehensive ProGuard rules in proguard-rules.pro:

• Kotlin/Kotlinx preserved
• Room database kept
• Compose reflection maintained
• Debug logs removed in production

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📦 Release Build

APK Size

• Debug: ~25-30 MB
• Release (with ProGuard): ~15-20 MB

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🤝 Contributing

This is a personal learning project demonstrating Kotlin Multiplatform capabilities. Feel free to fork and experiment!

Code Style

• Follow Kotlin coding conventions
• Use meaningful variable names
• Document complex logic
• Write tests for new features

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📝 License

• see the LICENSE file for details.

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🙏 Acknowledgments

• CoinGecko - Cryptocurrency data API
• CoinCap - Real-time price WebSocket
• JetBrains - Kotlin Multiplatform & Compose
• Coil - Image loading library
• Koin - Dependency injection

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📧 Contact

For questions or feedback about this project, feel free to open an issue.

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Built with ❤️ using Kotlin Multiplatform

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📸 Screenshots

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⚡ Performance

• Startup time: < 2 seconds
• Memory usage: ~150 MB average
• APK size: 15-20 MB (release)
• Smooth 60 FPS animations

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