Watch Later Tidy for YouTube™

This is a very nice extension. It's quite handy. Note that you have to turn off the ABP (AdBlock Plus) extension if you use it, otherwise this extension( YouTube Watch later tidy), will not work. Nothing will happen when you press the button because it opens in a popup that AddBlock Plus suppresses. Other pop-up stoppers might do the same thing. (Maybe the developer can detect these ad blockers and provide a warning.)