A GCM client is a GCM-enabled app that runs on an Android device. To write your client code, we recommend that you use the new
GoogleCloudMessaging APIs. The client helper library that was offered in previous versions of GCM still works, but it has been superseded by the more efficient
A full GCM implementation requires both a client implementation and a server-side implementation. For a step-by-step guide to creating a complete sample implementation that includes both client and server, see Getting Started.