gps
Is it possible to track the actual driven distance with the car in an Flutter App with Google Maps API?
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maps_toolkit | Dart Package
A library for area, distance, heading measurements (spherical_util.dart if port from android-maps-utils). In your dart/flutter project add the dependency: dependencies: ...

Implement Real-time Location Updates on Google Maps in Flutter
This is a very basic implementation of a location-based Flutter app that handles user's location changes in real-time.
https://medium.com/flutter-community/implement-real-time-location-updates-on-google-maps-in-flutter-235c8a09173e
geolocator | Flutter Package
A Flutter geolocation plugin which provides easy access to platform specific location services ( FusedLocationProviderClient or if not available the LocationManager on Android and CLLocationManager on iOS).
https://pub.dev/packages/geolocator