Google Cloud Messaging Server
By Fabio Uzeltinger
Engage your users across Android, iOS and Chrome.
Send data from your server to your users' devices, and receive messages from devices on the same connection. The GCM service handles all aspects of queueing of messages and delivery to client applications running on target devices, and it is completely free.
Versatile Messaging Targets.
Distribute messages to your client app in any of three ways ...