Android GCM permission GET_ACCOUNTS

On Android devices, GCM uses an existing connection for Google services. For pre-3.0 devices, this requires users to set up their Google accounts on their mobile devices. A Google account is not a requirement on devices running Android 4.0.4 or higher.

reference:

http://stackoverflow.com/a/18444343

https://developers.google.com/cloud-messaging/android/client