A sole add-on which is able to pin certificates! It helped me hundred times, especially when certificates change our of nowhere. Guys, this add-on will protect you from SSL stripping MITM attack - use it wisely

Great addon, deserves much more range

Love it. Very easy and intuitive UI

Let's you manually pin certificates and show an overview of them. Also shows you the current status in as a badge in the icon.
I like it!