This addon's not working properly. MP4's just give's a "the following content is not available on this app. watch this content on the latest version of youtube"
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 :(
