This extension displays grid and measurement overlays for a design grid system.
http://www.omega.url.tw/
http://www.felixniklas.com/
https://designer.tools
https://www.whatismyscreenresolution.org/
http://www.cswapps.com/
Malte Wassermann
Softpulse Infotech
leocompson
https://pixelmeasurement.com
https://responsiveviewer.org
https://csspeeper.com/
https://coolx10.com