STILL_SPARKLING  This used to be a handy little app, but I don't know what happened to this version. Previously, you'd install the app and a context menu item became available whenever you'd right click on a file or folder. You were then able to edit a single or multiple files in one smooth motion.

Now, however, the context menu item isn't available at all and when you open the program, it makes you navigate through a maze of folders from Finder just to edit one file. At a time! Or, you can drag the file or folder onto the Dukko icon. Laughably, it even nags you to donate after every operation.

Very sad that such a great little app has been degraded.   
(Version 1.6b5)

STONGEY  Looks neat, but when I open it in Tiger, a message box appears asking me if I want to download the Tiger version. I click OK, but nothing happens. I think it's linked to the author's old URL that is in the Read Me. Account no longer exists and the new webpage doesn't have the tiger version.  
(Version 1.6b5)

MEEGO  I had a lot of my AAC files' name truncated during a transfer Mac->PC->Mac. This resulted in a lot of "file not found" issues for tracks with long title.

This could be a life saver.  
(Version 1.6b1)