It works but the "X" is invisible on darker themes. Please give option for white or gray "X"

black on black is invisible

>v2.1: Add icon for dark theme.
How to enable them?

Not compatible with dark theme

Works like a charm!

may this addons have light color for dark theme :)

Does what it's supposed to. Only closes current window and leaves others open like it should.

Is just what I want.

instead of closing window it closes entire firefox

Well, this with the other "Maximize" and "Minimize" + "Hide title bar" Addons, you are good to go on Linux mint, no more ugly while using themes, because of the title bar.

Ok, it does what it has to, fast.
But, it would be more interesting (and more usefull!) to create restart button which will work in Web extention format.