Spotify mobile app were originally available only users who paid for its premium service, which left users of the free service stuck with listening to Spotify only on their desktops.But now, iPhone and iPad users can do the same using the Spotify mobile app, and best of all, they can do it for free. Spotify has today announced that it is added a new Pandora style radio service to its iOS app, providing both free and premium Spotify users in the US with access to the new service.Free Spotify users will have to listen to ad-supported radio, while paid users will get an ad-free experience.The update is,like Spotify's recently redesigned Android app,rolling out slowly, but Spotify has already made the update official.So check back later to grab the update.