android google play account auth

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http://stackoverflow.com – Is there any way to retrieve current google play logged user on an android device? I want to make an application that takes this username or userid from android and send it to one of my servers and like this authentificate the user on my service. I know there are multiple ways to auth trough facebook, twitter, google and many other providers, but i want to make it work without asking username and password. Thanks (HowTos)