At Google IO 2016 there was an announcement that GCM-3 is deprecated an the next version of Google Cloud Messaging is called Firebase Cloud Messaging.

For that there are some new APIs available, which actually have some nice and small changes, to be applied to our current GCM-3 APIs used in AGDroid.

All changes for a transition from GCM to FCM are documented here:
https://developers.google.com/cloud-messaging/android/android-migrate-fcm