Discussion: Flutter Module with Business Logic alone

# Discussion: iOS & Android existing App, Flutter Module with Business Logic alone

This issue has been made to discuss Add Flutter to Existing App.

## Summary
Is it possible to Add Flutter to Existing iOS/Android app without using FlutterViewController/FlutterView?

We are trying to integrate [FlutterBlue](https://pub.dev/packages/flutter_blue) or similar module in our existing iOS application.
I went through the following links, which explains Flutter Module integration in existing iOS/Android app,

https://flutter.dev/docs/development/add-to-app
https://blog.griddynamics.com/easily-move-your-native-app-to-flutter/
https://medium.com/flutter-community/add-flutter-to-existing-android-ios-app-ae8c4fb1582e

In all the above examples they are presenting FlutterViewController/FlutterView then pass data between Flutter and iOS/Android.
In our App we would like to replace the existing native BLE libraries with Flutter Module and use the existing UI screens.

So is it possible to use Flutter Module or call the Business Logic in Flutter Module without displaying FlutterViewController/FlutterActivity? (using [Pigeon](https://pub.dev/packages/pigeon))