A mandatory comment of the single most important tabs related feature, called "Simple tab groups" extension. https://addons.mozilla.org/en-US/firefox/addon/simp

A mandatory comment of the single most important tabs related feature, called "Simple tab groups" extension. https://addons.mozilla.org/en-US/firefox/addon/simple-tab-groups/ https://addons.mozilla.org/en-US/firefox/addon/simple-tab-gr... The rest IMO is just nice to have.