Google has made significant improvements to its Music app for Android devices.  The app was launched a year ago  with an initial 8 million tracks from top entertainment brands such as EMI, Universal and Sony Music Entertainment. The Android app allows you to shop for new tracks through Google Play and add up to 20,000 songs of your own. The new offline playback option allows you to share  playlists  with friends on Google+, who are able to play tracks in full via the service.

Google Music for Android new features

* Added ability to keep Thumbs Up, Last Added, and Free and Purchased playlists on device.
* Auto-generated Instant Mixes on Recent tab based on your favorite songs.
* Gapless playback support (on devices with Android 4.1 or later)
* Improvements for keeping music on your device for offline playback.