The app is a great help to all of us. As the number of features increases, there are several users that cannot install the app because of their mobiles (they are too old). On the other hand these useres wouldn't need the whole app, but only some basic features like:
This is something like a Black-Board-App with quite limited functionality, just right to the core of communications.
I thought it might be possible to provide a "reduced twin" of the app with reduced requirements (like Android 4.x or even older).