Receive share file intents with Flutter

You can use flutter-share, all info in Github

You won't have to meddle with java except for changing the MainActivity extends.

It is fully functional for Android, and the iOS part is currently being developed to match the Android part.

Update (2020):

Now you can also use receive_sharing_intent package. More info in pub.dev

There's a complete & simple example here - it includes everything you need both on the native side, and on the flutter side: https://flutter.io/flutter-for-android/#how-do-i-handle-incoming-intents-from-external-applications-in-flutter