This was mentioned in the Bartender hunt, so I thought I'd add it here. Looks useful — Quicksilver used to have a feature like this called "Shelf" which I couldn't live without. Now I just use DragonDrop.
Cool app :) $7 seems pricy for what it is though for some reason. Probably just what the app economy has does to my perception though. Really good idea!
Usually I use the CMD+TAB keys to toggle between windows, make the target active and then release the Mouse Button. Is there another scenario this app can help?