Sadly it's main function which was giving us the old Facebook layout back no longer works, due to Facebook blocking that from happening via a code change. But it is still a recommended add-on that's worth using, as this at least makes the horrid, new Facebook design a bit better on the eyes by bearing a resemblance to the way it was before. That despite even if it's now down to just strictly a cosmetic thing which merely puts lipstick on an ugly pig, and nothing more. It'll sort of help you get used to the new layout a bit better, and easier, as difficult as that'll be to do for at least a long while. That being the case with the site now becoming barely functional after this no good, unneeded drastic change it made now.