While there have been several apps designed to make ringtones, Apple has never allowed any app to actually copy the ringtone files into the system. You always had to do this back and forth dance with your computer. Until now!
* Requires iOS 6 or later
- Create custom ringtones and alerts for your iPhone, iPad, or iPod touch*
- Import songs from the Music library on your iOS device
- Play or record with GarageBand in the background while using other apps**
- Addresses a number of minor issues related to overall performance and stability
** Requires iPhone 4S, iPad 2 or later
Just to be super clear on those extra points at the bottom, iOS 6 is not required for this update! You will need iOS 6 if you want to import your own ringtones though. On iPhone 4S+ and iPad 2+ you can also now use background audio in Garageband!
Reader gatearray has already been playing with this and pointed out that since you can import anything into GarageBand with Audio Pasteboard, you could make a ringtone or notification out of just about any iOS music app!