Before there was Google Music, there was Subsonic. This app has attracted quite a lot of users for its ability to stream music that you have stored on your PC. The only trouble is that it has always been fairly ugly. This update solves that issue.
After installing the Subsonic app, you have to pick up the server software for the computer where all your media is stored. Sadly, this software will cost you $15, but there is a free trial. You can stream and cache mp3, ogg, aac, flac, wma files with Subsonic. The app also supports most video file types, but you need good bandwidth to pull that off. This update also includes ads, which you can opt out of with an in-app purchase of about $4 (yikes).
The financial investment is clearly more significant that the $0 Google Music costs, but you can manage your tunes locally and don't have to worry about authorizing devices. If you're already a Subsonic user, you should grab the update without reservation just on the basis of the UI change. See the old interface below to get an idea how major this overhaul is.