I have made an android application.
Now in the starting screen only i want to check weather the user has already registered or not. If he is registered then he should be directed directly to contact screen and if not registered then he should be directed to Registration screen.
Main question is: -
Without taking any input from user when he/she opens his/her application can we check that user is already registered or not.
Application can be used only by 1 user per phone.
Similar example like What'sApp chatting, one app per phone. so please guide me as soon as possible.