It used to work great. I don't know if it is because of Firefox or Facebook changes, but it just does not work on Facebook any longer.

I install this add-on only for one thing - to disable auto refreshing Facebook news feed. It work well! But when I found one side effects - you can't make posts on web version of Instagram. Always have a error "Your post could not be shared. Please try again". So sadly I can't use it(

Hey, I couldn't get your extension to work for my particular case. I'm trying to stop movies and videos or livestreams from freezing in the background. I noticed the videos freeze after 10 seconds if I open a different tab in fullscreen. But I did a lot of digging and I fixed it by going to about:config and changing media.suspend-bkgnd-video.delay-ms to a really high value. Might be something to look into

It broke some sites, but working pretty well, would be nice if the extension had a blacklist/whitelist feature.