This is a very simple application that does just one thing which was apparently left out of the OS.
If you've ever hit "Use as phone ringtone" in the music player by accident you probably had trouble *removing* the tune from the ringtone list. This app lets you do that, safely and easily. No more, no less.
NOTE: it is *not* intended to remove ringtones created by Ringdroid, Mabilo, etc. It is *just* for ringtones created via the music player. If it says "no deletable ringtones", it's because your tones weren't created from the music player -- please reread the previous paragraph if you don't understand this.
If you want control over all tones, try Ring Commander.