I know I get boring on this.... Magic Lantern, Live view, focus peaking. Works like a charm. Just have to flip between liveview and viewfinder. Also focus peaking is displayed in image review on the new version of Magic Lantern if you would just rather take a pic to check focus. Set your image review to several seconds and you can confirm focus. There are a couple of different settings for focus peaking to display (bright dots around the stuff that is in focus) with colors and % of pixels in focus, etc.