This sounds fantastic! Obviously it opens and reads the Aperture Library to get the statistics. Does it actually alter any of the files or folders in anyway? Does it create its own cache somewhere?
Also, how long will the introductory price be for?
I know that you can pretty much setup allsorts of filters in Aperture to see how you use your gear, but this sounds like a very fast and efficient way to see the stats.
Does it require a reading of the entire library every time it opens, or does it keep a cache and just looks at changes?