I think I can be of help here. Could you please let us know what the details are for this?
There are about 6 API for comunications, no signin, no signup, take example from eternitywall.it APP, but more simple.
Which framework do you use (eventually)? Do you develop for other mobile OS too?
I will be using Android Studio (if that is what you meant by framework). I do not develop for other OS's.