What do you think about recommended add-ons by Firefox, for example Tranquility Reader https://addons.mozilla.org/en-US/firefox/addon/tranquility-1/ https://add

What do you think about recommended add-ons by Firefox, for example Tranquility Reader https://addons.mozilla.org/en-US/firefox/addon/tranquility-1/ https://addons.mozilla.org/en-US/firefox/addon/tranquility-1... ? Their code is supposed to be checked by Firefox team, so it's probably safe to use.