GCM extension APIs make it easier to take advantage of enhanced messaging capabilities in your apps, and they can help you simplify your implementation of Google Cloud Messaging.
You can use GCM extensions in any new or existing GCM implementation to build powerful multi-device messaging and presence features for your users.
Streamlined registration makes it simple and fast to add GCM support to your Android app. Learn more »
GCM's Cloud Connection Service (CCS) lets you communicate with Android devices over a persistent XMPP connection. Communication is asynchronous and bidirectional, and you can use the service in tandem with existing GCM APIs. You can use this form to sign up for CCS. Learn more »
New user notifications let you send a single message simultaneously to all of a user's Android devices.
GCM lets you map all of a user's multiple devices to a single notification key, which you can then reference as the target for messages that you are sending to that user. Learn more »
The GCM Extension APIs are part of the Google Play services platform. To use the APIs, set up the Google Play services SDK.
To use GCM, you need to set up a Google APIs project and get an application key. If you are already using GCM, you can use your existing project and key. Learn more »
To send and receive messages over GCM, you need to update the manifest and add code to register with GCM and handle messages. See Get Started for details.
A complete GCM implementation requires a server-side implementation, in addition to the client implementation in your app. For complete information, make sure to read the Google Cloud Messaging documentation.