Just a menu?

From reading the description; I assumed I would be able to set my 27" 2560x1440 display to a few lower resolutions higher than 1280x720 in the same way the Retina MacBook Pro will let you run at 1920x1080. But all this does is let you switch between resolutions you can already switch between from the Displays Setting Panel. You still have to run the command line code to activate HiDPI.

MK500 about ResolutionTab