If all you want is a tab count and nothing else, it'll work as long as you don't have a dark theme.. For me, it had black text w transparent bg on dark theme.... had to pull up a magnifier app to read it.

This has no Preferences section so you won't be able to customize the bg/fg colors either. If this is something you need, you may want to check out: 'Tab Count Icon by lllusion3418', 'Tab Counter (Tilwa fork) by tqdv', or 'Tab Counter (fork) by vhfmag'


FF v89.0.2 on Fedora 33 Cinnamon