Before Firefox 57 release, I used to have an extension called Tab Mix Plus. One of the features that I liked, was the ability to have several lines to display the tabs list. I usually have dozens on tab opened on my browser, and scrolling horizontally to find the one I need is painful.

But Tab Mix Plus is now broken since Firefox has been redesigned. It is now considered as an obsolete extension. Unfortunately, I have not found a valid extension to replace it. Worse: extensions are not allowed to perform such changes in the new version of Firefox. ...