Thanks for development of this extension, but some key maps collide when watching youtube videos. For example, on a youtube video page, J moves video back by 10 seconds, and K pauses video. J and K have also used for scrolling down and up as you know. So problems rise on youtube pages. In addition to that, adding "http://www.youtube.com/*" to the blacklist doesn't work. So I unwillingly uninstalled this nice extension. Please work on this problem, because this extension seems pretty nice other than that problem.