A major new release of Xbox Music for iOS bumps the version number from 1.3 to 2.0 and adds the most sought-after feature: The ability to download music so you can listen to it offline. But this capability is curiously limited to playlists only. Hopefully that's a temporary condition.

Previous to today's update, Xbox Music for iOS—like Xbox Music for Android—was limited to online playback. So while you could browse and play your entire collection—your playlists, radio stations, artists, albums, songs, and genres—you could only do so while online. (You also need an Xbox Music Pass subscription to use this app on Android or iOS.)

With Xbox Music 2.0 for iOS, however, you can now download playlists—and not radio stations, artists, albums, songs or genres—to the device. And you must download an entire playlist, using a new "Available offline" switch you'll see at the top of any playlist view.

This option is new to the iOS app, of course, but it's also inconsistent with how Xbox Music works on other platforms that support downloading, including Windows and Windows Phone. There, you get selection controls and can download an individual song, any selection of songs, or an album.

The other thing to be aware of is that it's possible that just using this app will add your iPhone or iPod touch to your list of Xbox Music Pass devices. That's what happened to me: Even though I did not download a playlist, my iPhone is now one of my four Xbox Music Pass devices. That's unacceptable, as you can only remove two devices every 30 days. With other devices, that doesn't happen until you download something.

I'm hoping Microsoft fixes both of these issues—the inability to download songs or albums, at least, and the weird auto-enrollment of your i-device into your limited list of Xbox Music Pass devices. But for anyone that's been pining for offline support on an iPhone or iPod touch, this is a big update. And it's not terribly hard to create playlists of favorite albums and songs.

You can download Xbox Music for iOS from the Apple App Store.