I know that there's life span time for server-registered and the default value is 7 days, should I re-do the whole GCM registration process after 7 days?
And, how long is the expiration time for GCM registration once I registered?
com.google.android.c2dm.intent.REGISTRATION
intent may be called multiple times. Your Android application needs to be able to respond accordingly.Considering about the case if an user made GCM registered for an app, and then factory-reset the device, how could the app server side get aware of it?