A free program for Android, by Ventis Media Inc..
MediaMonkey Ringtone Maker is an add-on to MediaMonkey that lets you create ringtones or alarms from MP3, WAV, AAC, M4A, and other audio files in your MediaMonkey library.
Using this add-on, you can create a ringtone for each of your contacts, so you’ll never be without a good ringtone again.
You can set the tone for each contact as you receive a call or message. This is a very convenient way to keep track of all of your important calls and messages.
You can also set the tone for a specific contact or group of contacts, so you’ll know who is calling without even looking at your phone.