Responsive Design Checker was initially created in 2012 as an exercise for Media Genesis developers to see if they could create a tool that could be used to test websites for mobile design. Essentially, developers wanted to see how well certain websites could adapt when viewed on mobile device (like a phone) rather than just on a computer desktop.
As it turned out, it was a smash hit! But not necessarily with developers. Responsive Design Checker was appreciated more by non-development web users as it was able to determine if a website would be responsive while in mobile format.
Later updates to the system were made in 2015 in order to include a variety of preset screen sizes such as the 27-inch Dell Monitor U2711, 17-inch Workstation, 15-inch Macbook Pro, 11-inch Macbook Air, and the portrait and landscape modes of Apple’s iPad and iPhone, and the Nexus7.