A year or so back I wrote a little ffmpeg concatenation helper to make a friend's life easier. It was an OK shell script but it needed a config file to list all of the files that needed concatenation, and I wanted to just make a GUI that would let her add and reorder files to a list, then generate a temp file with the list (ffmpeg required the list to live in a file for some reason) and fire off the ffmpeg command to concatenate them both with and without sound.

This is apparently like a DEFCON 0 type operation to perform on a Mac requiring two guys in white lab coats to turn keys at the same time at opposite ends of the room, because there was no way to even ask for the permission to run the command if I remember right. It ended up being a case where I would be spending a ton of time to get more functionality than the command line script, so I quit. Plus it was one of those one plane ride projects.