It looks like Spotify's mobile offerings are catching up to its desktop brethren — the iOS version of the streaming music app now has an "extreme" quality option that'll bring 320kbps music to your device, just like the PC and OS X applications. Not all songs are available in the higher bitrate, and, of course, you need to have a $10 per month premium subscription to even use the mobile app. There's no word if the higher quality will make its way to Spotify's Android, Windows Phone, BlackBerry, MeeGo, Symbian, or webOS apps, though we would expect at least some of them will. The update (0.4.23) is available now from the iTunes App Store for all devices (read: iPhone, iPod touch, and iPad) running iOS 4.0 or greater.