WindowFlow isn't bad, but I would strongly recommend Witch over it. The only advantage WindowFlow has over Witch is window previews, while Witch has a boatload of other things you can do with it, like minimize windows, quit applications, cycle through windows of the frontmost application only, and define keyboard shortcuts for other useful window actions. If I didn't already own Witch, I might use WindowFlow since it was free, but for the money you're much better off with Witch, especially with a major upgrade on the horizon. I can't comment on the usefulness of any of the WindowFlow Pro features, but I already own SizeUp and Zooom, so I have no motivation to pay for the Pro window manipulation features. Unlike the previous poster stated, WindowFlow does not show up in my dock. It runs invisibly in the background and its application menu becomes available when activating it (the ability to run it in the dock or menu bar is apparently a Pro only feature). I don't agree with the one-star reviews below. I think this app is OK, though not necessarily worth its price simply because of its main competition.