Spotify for desktop computers allows users to listen to whatever they want anytime they want. It’s a great service that offers free listening to custom playlists and artists. Spotify also has a mobile app, but it’s not free. You need a premium account ($9.99/month) to access that. However, Spotify may soon offer a free service.
Unlike the desktop version, the free Spotify service on mobile will work more along the lines of Pandora or iTunes Radio. Rather than creating a custom playlist, you will select an artist or song. Spotify will then play music and artists similar to that.
It will be interesting to see how well this works. There are already tons of similar apps out there. The thing that differentiates the desktop version of Spotify from most of those services is the ability to create custom playlists. Once it got a strong foothold and became integrated with Facebook, it became one of the most popular streaming apps available.