This is an awesome add-on.
Especially if you keep like 200 tabs open. It allows to organize them in a simple way.

Dear Piro, I really need your help. Last version of Firefox seems to lose internet connection when TST bar is open. I know how strange it sounds, but I confirmed that on two computers already. Having TST installed does not break anything, but if you open the sidebar, connection disappears in the next minute. But the second I close the sidebar connection restores. I will check if the issue persists if I disable other add-ons.
Please get in touch at vwa8ypaq65ts@mail.ru. I would really hate to uninstall TST.
Thanks,
Alex.