Take a look at the above listing on Google. A ringtone editor you say? For a moment, I was so excited, then after looking at the changelog for Jelly Bean, it wasn’t there. Apparently they planned on releasing one, but they must of either trashed the idea or forgot about it, I hope it’s the latter one. Instead of having to do a bunch of editing on my computer to get a decent ringtone I could potentially do it all on my smartphone? Now that sounds helpful!
Android Police posted this image of a decompile:
Look at all that data just in the Music APK. There’s tons of files that are all based around the ringtone editor, so I wonder why we didn’t get it? My last phone, the LG Optimus V, had something similar in that you could select a song, touch and hold, and then set it as a ringtone. Apparently in the Jelly Bean update they were going to do that, except it would be an option next to something like “Add to playlist” or “repeat song” and etc.
I really wonder what happened because I would have loved this tool. Hopefully it shows up in the next version of Android.
source: Android Police