Still seems to work with FF20 Rated 4 out of 5 stars
As someone has told it here, using "Disable Add-on Compatibility Checks" add-on makes it work, and even on FF ver. 20. Tested on a Mac.
Hope the developper comes back, or at least makes the code open source so that someone else could continue with it.
Nice Rated 3 out of 5 stars
Incompatible with Firefox 13+.
This add-on works nicely.
It would be better with a more refined look and feel:
- play shutter sound when capturing finished.
- button appearance that better-suits the firefox UI.