The latest beta of Nokia's Ringtone Maker app has now been promoted to a full release in the Windows Phone Store. The update, version 188.8.131.52, includes support a wider range of file formats (MWA, M4A, WMA, AAC, plus the original MP3)and also increases the length of the maximum ringtone that can be created using the app from 30to 60 seconds.
As before the music files are drawn from the music collection stored on your phone and must be DRM free in order to be available to turned into ringtones. A simple editing interface lets you cut the ringtone in any way you like by specifying the start, end, and length of the ring tone. Once you've created and named the ringtone, it can be saved, and, optionally, be set as your current ringtone.
Windows Phone Store description:
With Ringtone Maker, you can create ringtones from the music on your phone. Simply open the app, select your favorite song and save it as a ringtone. You can cut your ringtone anyway you like, with editing controls that let you choose the start, end and length of your ringtone.
In this version there’s now support for more music file formats: WMA, M4A, M4R, and AAC along with MP3.