I was rooting around my system today, and wondering if there's any way to find out if an application is from the Mac App Store. The Info window - when you select an item and press Command-I - doesn't say anything, but the System Information application does. There is an "App Store" column which says yes or no for each application.
I figured there had to be another way, and eventually found that the mdls command gives some of this information. Running mdls <app name> returns a lot of information, but near the top of the list are a few lines like this:
$ mdls /Applications/Smarts.app kMDItemAlternateNames = ( "Smarts.app" ) kMDItemAppStoreAdamID = "438671026" kMDItemAppStoreCategory = "Music" kMDItemAppStoreCategoryType = "public.app-category.music" kMDItemAppStoreHasReceipt = 1 kMDItemAppStoreInstallerVersionID = "8330689" kMDItemAppStoreIsAppleSigned = 1 kMDItemAppStorePurchaseDate = 2012-06-13 07:14:43 +0000 kMDItemAppStoreReceiptType = "ProductionReceipt"
Mac OS X Hints
http://hints.macworld.com/article.php?story=20120731002309128