I looked into it, and there's really not a great way of doing it. Kinda shocked Google hasn't released an app yet.
Yes, just look up Melodies or gMusic in the App Store.
The gMusic app will show the listing of any song that you add to the library but it won't play unless you purchased the individual song.
You couldn't have looked hard....
Second post in this thread.
Playlist syncing, offline caching, background playback and lockscreen controls, last.fm scrobbling...
Not sure what isn't great about it?
My uploaded and bought songs work fine on gMusic.
All-Access is working for me via gMusic.
I think the promo price difference may convince me to drop Spotify now but will give it the month to decide. So far so good, I've been pleasantly surprised at how comparable the catalogue is.