Firebase Cloud Messaging (FCM) is the new version of GCM. Built on top of the GCM infrastructure, it provides the ability send messages to multiple platforms beyond Android: iOS and Mobile web.
In this tutorial, we will see how to configure and use Firebase Cloud Messaging platform in your Android application. Visit my blog for complete tutorial http://stacktips.com/tutorials/android/how-to-integrate-firebase-cloud-messaging-for-android