YouTube NonStop v0.9.2 
Kiss the annoying "Video paused. Continue watching?" confirmation goodbye!
Important: This extension doesn't keep the confirmation box from popping up. It only counters it. It auto-clicks the confirmation box and keeps the video unpaused.
Now with Media Keys support (read below)!
Working on YouTube and YouTube Music!
In your Firefox media keys may be disabled. To enable the functionality:
1. Navigate to about:config from your address bar
2. If there is a warning message just confirm that you understand the risks
3. Search for media.hardwaremediakeys.enabled and set to TRUE
3. Search for dom.media.mediasession.enabled and set to TRUE
4. Restart your browser
Untested (but should work) when: Video is in fullscreen, Video is in miniplayer.
If you have any problems, don't hesitate to drop me an email. :)
Tags: music youtube