Rated 4 out of 5 stars

Works nicely as expected. Only flaw is there was no locale support. For the sake of future development and hence to conquer the world :) I propose a version with locale support (en-US only atm) here http://babelwiki.babelzilla.org/images/c/c9/Fullfullscreen_locale_support.xpi Of course you are welcome to submit on http://www.babelzilla.org to get more languages for free.

This review is for a previous version of the add-on (4).