Obaje FX Converter

Joseph Obaje's personal currency converter: a Flutter (Material 3) app with live exchange rates.

Author: Joseph Obaje
App ID: com.josephobaje.forex_converter (Android/Linux), com.josephobaje.forexConverter (iOS)

• Convert tab: amount, from/to pickers, swap, live result, rate used (both directions), fetch time and provider update time. Default USD → NGN.
• Rates tab: rates of all supported currencies against a selectable base (default NGN), pull-to-refresh, last-updated timestamp.
• Currencies: NGN, USD, EUR, GBP, CNY, GHS, ZAR, KES, XOF, XAF, EGP, AED, SAR, INR, CAD, JPY, CHF, AUD (edit lib/src/currencies.dart).
• Rates: open.er-api.com (free, no API key, CORS-enabled, updated daily). Cross rates are derived from the USD-based snapshot.
• Offline: last successful response is cached in shared_preferences; cached or >24h-old rates show a "may be stale" banner.
• Light/dark follows the system theme (deep teal Material 3 colour scheme).
• In-app credit on the Rates tab: "Rates by ExchangeRate-API · https://www.exchangerate-api.com".

Structure

lib/main.dart                           entry point
lib/src/app.dart                        MaterialApp, themes, bottom navigation
lib/src/models/rates_snapshot.dart      parsing, cache JSON, conversion math
lib/src/services/rates_repository.dart  HTTP fetch + local cache
lib/src/state/rates_controller.dart     ChangeNotifier app state
lib/src/screens/                        converter & rates screens
lib/src/widgets/                        currency picker, status banners

Commands

flutter pub get
flutter analyze
flutter test
flutter run            # device/emulator or -d chrome
flutter build web      # output: build/web
flutter build apk      # requires Android SDK

Rates by ExchangeRate-API (https://www.exchangerate-api.com); their free terms require attribution.