I am releasing a Google Music channel that should work for all Plex clients. I forked the current channel created by the user Maik and added a bunch of new features. If anyone has any issues please post your log files and I will be happy to take a look. Also, if you have any request for new features please let me know. I will be sending out a request to get this added to the Unsupported Appstore as well.
If you are running into any issues please post your log files. I won't be able to help you without them.
Github:
https://github.com/jwdempsey/GoogleMusic.bundle
Updates
6/03/2014
NEW: Added I'm feeling lucky radio
FIXED: Songs should play correctly for users without All Access
FIXED: Genres and Search can only be accessed by All Access users
6/11/2014
FIXED: Fixed an issue where if you only had an iOS device registered then you couldn't stream
8/13/2014
IMPROVEMENT: Large libraries can now be loaded without timing out
11/11/2014
NEW: Public playlists are now returned in search results
NEW: You can now add songs to playlists/library from the search menu
IMPROVEMENT: I improved library how your library is cached. You should see new songs much sooner now.
12/06/2014
NEW: Added new menu to show songs by letter
04/01/2015
NEW: Added new menu option to manually refresh library data. Library data will also refresh every 2 hours automatically.