page.title=Google Cloud Messaging for Android @jd:body
Google Cloud Messaging for Android (GCM) is a service that helps developers send data from servers to their Android applications on Android devices. This could be a lightweight message telling the Android application that there is new data to be fetched from the server (for instance, a movie uploaded by a friend), or it could be a message containing up to 4kb of payload data (so apps like instant messaging can consume the message directly). The GCM service handles all aspects of queueing of messages and delivery to the target Android application running on the target device.
GCM is completely free no matter how big your messaging needs are, and there are no quotas.
To learn more about GCM, you can join the android-gcm group and read the following documents:
GCM also provides helper libraries for client and server development.