Rated 5 out of 5 stars

Good, but At first with no instruction, hard to find settings pannel. please add context menu on toolbar for settings :)

This review is for a previous version of the add-on (1.7.4.1-signed). 

Indeed.

As I said in my developer profile (https://addons.mozilla.org/en-US/firefox/addon/translate-this/developers) this is something I want to fix. Unfortunately with the current state of the Addon SDK there is no way to add a context menu to the toolbar, but this is something that I will do when the feature becomes available.