That is built in uBlock Origin.<p>Click the eyedropper tool &quot;enter element picker mode&quot; <a href="https:&#x2F;&#x2F;www.dropbox.com&#x2F;s&#x2F;niy881lyaca4zmx&#x2F;Screenshot%202016-01-28%2018.14.09.PNG?dl=0" rel="nofollow">https:&#x2F;&#x2F;www.dropbox.com&#x2F;s&#x2F;niy881lyaca4zmx&#x2F;Screenshot%202016-...</a>