Cool and Simple Rated 5 out of 5 stars

Hey thanks for developing this.
It works great and will come in handy.

When it's first installed and a user opens the Customize Toolbar window to add the Screen Draw toolbar button, all that is shown is the the text for it and after dragging it to a toolbar, no icon is shown until it's clicked.
That can be fixed with the following.

#screendraw-toolbarbutton {
list-style-image: url("chrome://screendraw/skin/statusbarbutton_disabled.png");
Or whatever image you want.

You use screendraw-toolbarbutton for the toolbar button's id in the xulref.xul, but in the style.css, there's no image associated with it.

I'm by no means an add-on developer pro, far, far, from it and could use help.
I just wanted to figure out the button issue to learn from it and this is what I came up with.