Flutter Background Geofencing & Notifications

I already have a FlutterFlow-exported project that pinpoints when a user is within ~40m of a saved spot while the app is open. Now I need the same detection to keep running in the background (minimized, locked, or screen off) on both iOS and Android — and to raise a local notification the instant the user enters the area.

Requirements

Integrate background geofencing that survives minimize, lock, and app kill.

Trigger a standard local notification (“You’ve arrived!” style) within seconds of entry.

Behaviour should feel seamless, like Uber or Strava.

Work inside the existing Flutter codebase (Dart preferred).

Acceptable packages: flutter_background_geolocation, geolocator, workmanager, flutter_local_notifications. A small native plug-in is fine if required.

Must be fully compliant with App Store + Play Store policies.

Optimized for minimal battery drain (use OS-level APIs, no polling).

Deliverables

Updated Flutter project with background geofence + instant notification logic, verified on iOS + Android (latest versions).

Setup notes: Info.plist, AndroidManifest, permission prompts, battery exceptions.

Simple test routine (simulated coords or adjustable radius) so I can confirm notifications fire without travel.

Acceptance Criteria
With the app killed or asleep, entering the defined region shows a local notification within seconds on my physical iPhone and Android test devices. No UI redesign or server work needed.