Currency Converter Calculator

A modern Flutter application for currency conversion with built-in calculator functionality. Supports both fiat currencies and cryptocurrencies with real-time exchange rates.

Features

• 🧮 Built-in Calculator - Perform calculations and instantly convert results
• 💱 Multi-Currency Support - 150+ fiat currencies and 100+ cryptocurrencies
• 🔄 Real-time Exchange Rates - Automatic updates from exchangerate-api.com and CoinGecko
• 💾 Offline Mode - Cached exchange rates work without internet
• 🎨 Modern UI - Clean Material Design 3 interface with dark mode support
• 🖥️ Cross-Platform - Runs on Linux, macOS, Windows, Android, iOS, and Web

Tech Stack

• Flutter - Cross-platform UI framework
• Riverpod - State management
• Hive - Local NoSQL database for caching
• HTTP - API communication

Quick Start

Prerequisites

• Flutter SDK (3.9.2 or higher)
• Dart SDK

Installation

# Clone the repository
git clone https://github.com/jozef-pridavok/converter.git
cd converter

# Install dependencies
flutter pub get

# Run the app
flutter run

Platform-Specific Builds

# Desktop
flutter run -d linux
flutter run -d macos
flutter run -d windows

# Mobile
flutter run -d android
flutter run -d ios

# Web
flutter run -d chrome

Usage

1. Select Currencies - Tap currency to choose from fiat and crypto currencies
2. Enter Amount - Use the built-in calculator keypad to input values
3. Auto-Convert - All conversions happen instantly across all selected currencies
4. Refresh Rates - Tap the refresh button to update exchange rates

Configuration

API endpoints and settings can be configured in lib/services/api_exchange_rate_service.dart:

class _Config {
  static const String fiatApiUrl = 'https://api.exchangerate-api.com/v4/latest/USD';
  static const String cryptoApiUrl = 'https://api.coingecko.com/api/v3/coins/markets';
  static const String baseCurrency = 'USD';
  static const int requestTimeoutSeconds = 10;
}

Architecture

lib/
├── config/          # Configuration constants
├── models/          # Data models (Currency, ExchangeRate)
├── services/        # Business logic (API, Database)
├── providers/       # Riverpod state management
├── ui/
│   ├── screens/     # Main application screens
│   └── widgets/     # Reusable UI components
└── utils/           # Utility functions (NumberFormatter)

Contributing

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

License

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

Acknowledgments

• Exchange rates provided by exchangerate-api.com
• Cryptocurrency data from CoinGecko API