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