I’m building a travel-and-navigation app in Flutter that must run smoothly on both iOS and Android. The core of the project is reliable GPS tracking that stays alive in the background without draining the battery. Location data will be stored in a Firebase backend, with cached copies kept locally so the app remains fully usable when the device is offline. The UI can stay simple for now—clean screens for the map, trip details, and a settings page—but the code architecture should be solid and easy to extend later. All Firebase services (Auth, Firestore, Cloud Functions if needed) need to be wired up, and I’ll rely on your guidance for the best practices in handling location permissions across platforms. Deliverables: • Complete Flutter (Dart) source code • Background location service with battery-saving best practices • Firebase integration (Auth, real-time data storage, secure rules) • Offline data layer that syncs automatically once a connection is restored • Platform-specific setup instructions and a short README so I can run the project locally and submit it to both stores If you’ve shipped background GPS apps before and know how to squeeze every bit of efficiency out of Flutter’s location plugins, this should be a straightforward build. Let’s get started!