Doesn't work. Used to until a couple days ago. Apparently Youtube is now charging to download and as far as I can tell, Youtube has stopped this app dead in it's tracks.
Looking at other reviews, I see other people tried paying. Still didn't work. So I won't be trying that myself.
I have fixed this and you will receive an update via auto addon update in firefox once it is reviewed there. If you are on Google Chrome or Microsoft Edge you need to manually update by visiting this download page.
It's disheartening that many satisfied users don't leave reviews while a few unsatisfied ones do, that too after using it for years but not working for few days :(
