4.9.21a1 works! Rated 5 out of 5 stars

My Innert00bz connection is a little iffy, which makes streaming videos a shaky proposition at best, so I DL pretty much everything I want to watch. In short, this extension makes YouTube possible for me. I was so upset when it stopped working…it's FINALLY working again thanks to the new 4.9.21a1 version (which has to be DLd from their site, see July 26the update above)!

This review is for a previous version of the add-on (4.9.21).