Spotify has submitted its iPhone app to Apple for approval for the iTunes App Store.

The app will only work for premium users of Spotify, who pay £9.99 ($16.50) in the U.K. for a higher quality, ad-free version of the free ad-funded streaming service.

Spotify expects the app to be available within a few weeks and it posted a demo here.

The app will work in areas such as London Underground where there is no network coverage. "The application has an offline mode that allows users to temporarily cache playlists to their phone for use when there is no connection," said a Spotify statement.

It is understood the Spotify app will be free.