The best first person shooter in the App Store

Modern Combat 4: Zero Hour ($6.99) is the latest installment from Gameloft's hit first-person-shooter franchise, and while it borrows heavily from the Call of Duty games, you can't beat the nonstop action and smooth realistic graphics. Play single-player campaign mode or try your luck against other players in a fully fleshed out online multiplayer mode. Watch out, though, some of those guys are good.