Sugar Rush
It's widely accepted at this point that sugar is bad for you — especially the processed sugar that gets added to foods in an effort to make them more addictive/taste better. Sugar Rush lets you know just how much sugar has been added to anything you're thinking of eating just by scanning the UPC code. It shows you how many teaspoons (or, scarily, tablespoons) have been added, as well as the ratio of naturally occurring sugars to unnecessary additives. And since it works from anywhere you can get Internet, you can make the smart, healthy decision before you throw the stuff in your cart.
