I want to create an Android application that shows ongoing events to users (missile launches in different regions, based on the user's location. This isn't a game, it's one of the perks of living close to Gaza).
I can use GCM for push notifications, but I have to do this on a device-by-device basis. I would like instead to offer a few subscription channels based on the client's location, and send data from the server to all clients listening to that channel.
Is there a Google API for this, or do I have to implement it myself (maybe by using XMPP), reducing battery life quite a bit?