Make a Cryptocurrency Tracker App with Flutter

What This App Does

A Cryptocurrency Tracker app serves a specific need in today's mobile-first world. Building one with Flutter means you ship to iOS, Android, and the web from a single codebase, cutting development time dramatically while keeping a native-quality experience.

Main Features

Feature	Why It Matters
Live Price Feed	WebSocket connection to an exchange API for real-time price updates
Portfolio Tracking	Log purchases and sales; calculate P&L and percentage change
Alert System	Push notification when a coin hits a user-defined price threshold
Charts & History	Interactive candlestick or line charts over 1D, 1W, 1M, 1Y periods
Watchlist Management	Curated list of favourite coins with drag-to-reorder

How to Make a Cryptocurrency Tracker App with Flutter

Live Price Feed

class PriceService {
  WebSocketChannel? _channel;

  Stream connect(String symbol) {
    _channel = WebSocketChannel.connect(
      Uri.parse('wss://stream.binance.com:9443/ws/${symbol.toLowerCase()}@trade'),
    );
    return _channel!.stream
      .map((data) {
        final json = jsonDecode(data as String);
        return double.parse(json['p']);
      });
  }

  void disconnect() => _channel?.sink.close();
}

// Usage in widget:
// final service = PriceService();
// service.connect('BTCUSDT').listen((price) {
//   setState(() => _currentPrice = price);
// });

Portfolio Tracking

class PortfolioHolding {
  final String coin;
  double amount;
  double avgBuyPrice;

  PortfolioHolding({required this.coin, required this.amount, required this.avgBuyPrice});

  double get currentValue => amount * _currentPrice;
  double get pnlPercent => ((_currentPrice - avgBuyPrice) / avgBuyPrice) * 100;
}

class PortfolioProvider extends ChangeNotifier {
  final List _holdings = [];
  Map _prices = {};

  void addPurchase(String coin, double amount, double price) {
    _holdings.add(PortfolioHolding(coin: coin, amount: amount, avgBuyPrice: price));
    notifyListeners();
  }

  void updatePrice(String coin, double price) {
    _prices[coin] = price;
    notifyListeners();
  }

  double get totalValue => _holdings.fold(0, (sum, h) =>
    sum + h.amount * (_prices[h.coin] ?? 0));
}

Recommended Libraries

Package	Purpose
web_socket_channel	Real-time price stream from exchange APIs
fl_chart	Interactive candlestick and line charts
flutter_local_notifications	Price alert push notifications

UI & UX Suggestions

Use a dark theme (#0d1117), green/red for gains/losses, orange accent colour palette to match the app's purpose. Keep the navigation simple — a bottom nav bar or a single-scroll layout works best for this type of app. Make sure every interaction provides haptic or visual feedback so the app feels responsive and polished.