improve 1) hotkey setting; 2) description of what parameter D is; 3) turn it off with the Esc button; 4) reduce the font size.

good

very useful. add please hotkeys for open and close

Work as its name. I wish this extension can change background color of selected area to be easier to read

Simples, sehr gelungenes Addon für Web Worker und Webmaster, die öfter mal Maß nehmen müssen. Danke.

Working as expected !

ps : A clipboard option would be great, with css format that including position and dimensions of the div, as this for example :
left: px;
top: px;
width: px;
height: px;

Thanks for your job ;)