title: Open Android Activity and iOS ViewController from Flutter
body: <p>I have a Flutter project that requires some certain features that needs to be implemented in native Android Activity or iOS ViewController. is there a way to navigate to android Activity and pass data to it and also retrieve data from it in Flutter?</p>
  <p>and if it's impossible, is it possible to show an Activity or fragment from Android, and a ViewController from iOS, as a Widget in Flutter?</p>