Gift cards are supposed to be pleasant surprises, but they can frequently be headaches; assuming you remember to bring them in the first place, you have to keep tabs on any leftover credit. They should be easier to manage after today, though. Google has just rolled gift card support into the Wallet apps for both Android and iOS. All you have to do is either snap a photo of a card or type in its info. After that, you can safely leave the plastic at home. Some merchants, such as AMC, Best Buy and Whole Foods, will also show the remaining balance on their cards.