Our iPhones make it easier than ever to keep our budgets in check. There are an abundance of spending trackers in the App Store that will alert us when our bills are getting out of hand, but they're really only as smart as we make them. Constant vigilance is required to catch errant charges, and if you're not careful, fees and fraud can pile up and siphon money from your wallet. BillGuard looks to take human error out of the equation. By leveraging the power of crowd-sourcing, the app scans every credit and debit card transaction and alerts you to anything that looks suspicious.