Push Notifications in Android Platform

Google's official answer is the Android Cloud to Device Messaging Framework (deprecated) Google Cloud Messaging(deprecated) Firebase Cloud Messaging

It will work on Android >= 2.2 (on phones that have the Play Store).

(cross-posting from an answer I gave to a similar question - Does Android support near real time push notification? )

I recently started playing with MQTT http://mqtt.org for Android as a way of doing this sort of thing (i.e. push notification that is not SMS but data driven, almost immediate message delivery, not polling, etc.)

I have a blog post with background information on this in case it's helpful

http://dalelane.co.uk/blog/?p=938

(Note: MQTT is an IBM technology, and I should point out that I work for IBM.)