🌕 CoinRanking iOS App

An iOS app that displays real-time market data for the top 100 cryptocurrencies, including price, performance, and detailed analytics — built using Swift, UIKit, and SwiftUI. The app supports swiping to favorite coins and filtering by price or performance.

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📲 App Screenshots

Splash	Home (Top 100)	Coin Detail	Favorites

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📦 Features

🔢 Screen 1: Top 100 Coins List

• Paginated (20 coins per page).
• Swipe to favorite/unfavorite.
• Filter by:
  • Highest price
  • Best 24-hour performance
• Display includes:
  • Icon
  • Name
  • Current Price
  • 24-hour % change (green/red)

📊 Screen 2: Coin Details

• Coin name, price, statistics
• Interactive performance chart with time filters

❤️ Screen 3: Favorites

• List of all favorited coins
• Swipe to unfavorite
• View full details of each coin

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🛠 Tech Stack

• Swift 5
• UIKit – navigation, table views
• SwiftUI – lightweight reusable views
• SPM(SwiftPackageManager) – dependency manager for Lottie
• Network.framework – for real-time connectivity check
• MVVM – maintainable architecture

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🔧 Setup Instructions

✅ Requirements:

• Xcode 14 or later
• iOS 14+ simulator or device

📥 Installation

1. Clone this repo

   https://github.com/kelvinofula/CoinRankingApp.git
   cd coinranking

2. Create a free CoinRanking API account

   • Visit https://developers.coinranking.com/
   • Sign up and generate your Test API Key

3. Configure API Key securely

   • In the Xcode project root, create a new file: secrets.xcconfig
   • Copy contents from secrets-sample.xcconfig and replace with your real API key:

     API_KEY=your_api_key_here
     

   • In Xcode:
     • Go to Project > Info > Configurations
     • Add secrets.xcconfig to the Debug configuration via the File Inspector

4. Run the project

   • Open CoinRanking.xcodeproj
   • Build and run on a simulator or connected device

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✅ Good Practices Used

• Immediate network status using monitor.currentPath.status to avoid false negatives
• Swipe-to-favorite updates both UI and data store safely
• Clean MVVM separation between view, presenter, and store
• Memory-safe singletons (e.g. NetworkMonitor.shared)
• Lottie animation integrated via Swift Package Manager

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🧪 Testing

• Unit tests for:
  • FavoritesStore logic
  • Presenter-state formatting
• Placeholder test targets included for extensibility

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📄 Assumptions & Design Choices

• In-memory favorites store for simplicity (can be extended with CoreData or UserDefaults)
• NavigationController used for view transitions
• Placeholder Lottie animation for splash
• Simple bar chart with toggle buttons in the coin detail (replaceable with Charts framework)

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⚠️ Known Issues

• If API key is not configured properly, the app will fail silently. Confirm via console logs.
• Some chart animations are simulated and do not reflect real-time data yet.

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🧠 Challenges & How I Solved Them

Challenge	Solution
NWPathMonitor reports false on first check	Used monitor.currentPath.status for immediate snapshot
Inconsistent state after swipe favorite	Synced UI state with model + refreshed data source
Lottie integration in UIKit views	Used LottieAnimationView and animated it on the splash screen

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✨ Future Enhancements

• Persist favorites using UserDefaults or CoreData
• Integrate real-time graph with Charts or Swift Charts
• Add search functionality to filter coins
• Dark mode and accessibility features

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📬 Submission

This app was built for an iOS take-home assessment and demonstrates:

• UIKit + SwiftUI integration
• API pagination and filtering
• State management and animation
• Production-quality practices

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👨‍💻 Author

Kelvin Ofula
LinkedIn
GitHub

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🪪 License

This project is open-sourced under the MIT License.