Sadly does not support properly facebook anymore. Videos like relations, rolls etc can not be downloaded because the add-on icon does not shows up on those media like it did previously.
Additionally the user-script variant of the add-on notoriously popups very irritating ads on the pages about some "OrangeMonkey" add-on. Those can't be disabled or turned off.
Sorry folks, but I won't use such OrangeMonkey junk just because you want me to use it.
Just f-off with that crap please!
Such nasty behavior should be also reported to Mozilla due to the violation of their rules!