First, it doesn't work. Second, the implementation is weak. My sites use a mobile detection script and they send the desktop site, not the mobile site, pages. Second, having the mobileview in a menu window is clunky and ignores that a lot of mobile devices have laptop size screens.
this stuff doesn't work for me on Firefox 31.3... I think MobileView addon should show responsive websites properly, which means responsive and not full-page layout with scrollbars. Please check it up and I hope this addon would be awesome without bugs like this.
Working but not sure why I am going to use it. When I click on main window then the Mobile view should stay! and if it can take value from main view then I can edit (firebug) and see the change both ways.