With so many apps today at affordable prices, it's easy to lose track of how much you spend on them after a while (which is undoubtedly the way Apple wants it). Now a tool has been released for the Mac that will tell you just how much money you have invested in software on your iPhone. Fittingly dubbed the App Store Expense Monitor, it scans all the apps you have in iTunes, checks their prices in the App Store, and calculates a total.