Рейтинг 2 из 5 звёзд

Needed for FF 3.5

A quick and easy button to the new
PRIVATE BROWSING function.

Then I'll download this app.

Ta mucho chappies

Это отзыв для предыдущей версии этого дополнения (0.1.2). 

giving a low rating isn't going to make me add them any faster

and you didn't say which extension so i'd guess this one?
https://addons.mozilla.org/addon/9517

or are you asking me to add a button (my extension just adds icons not buttons or menuitems)?