iTunes link: Spotify – Free, but £10 monthly subscription required.
Spotify is everybody’s favourite free music streaming services, but if you want to use the iPhone app you’ve got to sign up to the company’s premium subscription option. Obviously the service’s key feature is the millions of tracks that are available to you to stream to your phone.
However, the iPhone version also lets you save playlists of tracks to your handset so that you can play them when your phone is out of range of an Internet connection. Syncing tracks takes place over the air on Wi-Fi or 3G, although it's more sensible to do the initial sync over Wi-Fi. On the whole, the app is excellent, but there are a few omissions such as the way you can’t delete playlists and the lack of access to related artist info.
It’s not yet perfect, but Spotify still provides a great way to access an enormous library of tunes.