Android app: logging in using google ID?

Well hello guys.

I am in progress of creating an android app that requires you to register and login.

Now I was th开发者_JS百科inking, why register and login? Isn't it possible to automaticly login with the google account that is already on your device? Just like how you can use your google account to login to stack overflow?

So my question is: is this possible, and how?

Thanks!

I guess you could use Google's OAuth service to check if the supplied account / password combo is valid. Save the token and require them to login again if they logout, to verify the account / password again.

You could even have access to some of their Google Apps data from this point, if you wanted.