Hi there,
In search of FF57 compatible addon I've picked on this one as the most promising.
However I have some suggestions about styling.
Currently the styling of the menu items is a bit off comparing to default one (library entries).
Is it possible to update this to become a perfect match with a browser?
Maybe this will help.
https://mozilla.invisionapp.com/share/ENBBK0F9U#/screens/229252106
Also an update to button would be neat
http://design.firefox.com/photon/visual/icons.html

"Click the image one time to undo the last closed tab. Three times to open the last three closed tabs and so on"

It doesn't work that way, when i click once i get the context menu.
Also the font and icons are weird. Here is how it looks in the advertised picture and how it looks in mine: http://i.imgur.com/XzJT1yQ.png
Firefox Nightly v56

But the last two menus don't work.

Edit: Installation problem is gone.

Works like it used to, i just dont like the orange icon, which is just a minor issue.