Tab List Sidebar od Russell

Note: I have since discovered Tab Center Reborn which already has all the things I was hoping to some day include in this addon. Shout out to Mélanie for a great addon! Go check it out.

Got so many tabs open in Firefox that you can't tell which is which? Open the Tab List extension and you'll get a list of all of your tabs in a sidebar view. Click on an item to switch to that tab.