Radio is the latest addition to Spotify's iOS apps, which allows users to take the streaming music service's Pandora-like functionality on the go. But this isn't just for the people with premium accounts. Anyone can listen to Spotify radio on their iOS device for free.
European users have enjoyed this feature for ages now, but US Spotify fans can now—finally—create their own radio stations with the popular application. It basically lets you mix different genres together to create a custom mix.