Circloid is a retina-ready and responsive Admin theme for OpenCart. Circloid allows you to change the look of your admin to suit your style. It's a complete redesign of the default theme but does not overwrite it. It uses vQmod, so nothing is overwritten on your site. All you have to do is upload the files to the respective locations and you're set. So you can always go back to the default theme whenever you wish. It's responsive too (built on bootstrap) so it looks great when you're on your mobile device.