I put one star to get your attention, it is no longer working on Firefox for Mac. When I enable it it says browser is not supported and puts everything in the old mobile layout. When I turn it off it widens it, but when I restart it goes back to the new crappy layout. Before it was great!!!
YOU SAVED MY LIFE !!!!!!!!!!!!!!!!!!!!!!!! ------ 21 oct 2020 : Messenger does not work anymore :( 25/10 : does not work - Old layout is dead for me :(