Would be great if you could set icon to simple "plus" sign

Easy, simple, and it does its job :-)

Perfect and great after you switch to a vertical tab bar with Sidebery!
Doubleclicking anywhere on Sidebery works well, but on autopilot I am looking for the + sign on the top right area.

Спасибо тебе, добрый человек!

Thank you for a very useful add on that is something so basic that Firefox should have included it automatically in their collection of customizable buttons. It's especially useful and almost vital if you've modified Firefox so that the tab bar is hidden when you only on tab open.

Thank you! Dead simple addon, all I needed was an extra button for new tab. Works perfectly. I would just add an option to change the icon...

So simple, so good!