Sony has just released its Music Unlimited streaming app for iPhone, opening up the service to many more users who don't have Sony devices. Music Unlimited is similar to Spotify or Rdio in that it lets you stream songs and albums, make playlists, and a listen to and customize channels to your tastes. We've been hearing that the app was going to make its way to the iPhone for some time now, and now that it has the music platform is spread across Android, Walkman PMPs, the PS Vita, and other Sony home theater products like Blu-ray players and TVs.

There's no iPad app yet (we're told there will be one, eventually), but the Omnifone-powered service comes in two different flavors: a $3.99 per month basic plan and a $9.99 per month premium one. Only the latter lets you stream unlimited songs and albums of your choosing — the basic plan limits you to a selection of channels that you can customize by liking or disliking particular tracks. On the cheaper plan the only way you'll be able to listen to individual tracks is to match them with Sony's catalog from your PC library, but thankfully there are no limits on how many songs you skip when listening to genre-specific channels and there are no ads. If you're more interested in listening to music on demand, you'll have to go for the premium plan, which also lets you save tracks for offline listening. For now it looks like only New Zealanders have access to the app, but it should be available elsewhere soon.

Update: Sony tells us the app will spread to all sixteen countries that offer the Music Unlimited service on May 25th, and that the upcoming iPad version is a priority for the company.