I want user to register before access the android app.
The username will be email address.
Somehow i want the user to confirm his email because its the only way he can recover his password if he forgets it.
So i found there are two occasions he can confirm his email.
1) User activation link sent to his email and he click it. Till that time he is not allowed to login in
2) User confirmation link send to his email and he clicks it. Till that time he is allowed.
The first method has no ambiguity because unless the user clicks the activation there will be not be any way to move ahead. But it can be little uncomfortable to the user because he have to wait.
the second method is bit confusing in regard to how long we have to keep informing the user to confirm his email. And we have to restrict access to certain features til he confirms his email.
Which is the better and keep it simple way