Google Play Music taps into Google's extensive music library and uploads and stores your own music collection in the cloud. The only downside is that you can't purchase songs and subscriptions directly from the app.
After installation, Google Play Music will ask you to sign in to your Google account, but if you're using any other official Google apps you will be signed in, automatically. The product comes free of charge, but in order to have access to Google's full library of songs, a $10-per-month subscription is required. While testing, the app proved to be silky smooth, but we kind of expected that. In terms of features, you can choose to download albums for offline listening, but there isn't a way to download individual songs. Another nice feature is its streaming radio service, which gives you the ability to create radio stations based on an artist or song. Unfortunately, you cannot create them based on genre.
If you're looking for a free way to have your music collection online and access it from any device and platform, Google Play Music is the way to go. While there are certainly things to improve, the number of supported platforms and features such as offline downloads make it a good all-in-one app for listening to music.