When the dead rise, it might not be clear who is on your side, and who is hungry for human flesh. The Zombie Survival Guide Scanner purportedly allows users to detect zombies among human survivors, though, unsurprisingly, reviewers bash the app as a silly marketing gimmick. Another smartphone app, Map of the Dead, maps out where nearby hospitals, hardware stores, retailers selling weapons, and other buildings that may be useful during the apocalypse are. This is assuming, of course, you’ll still have cell phone reception and access to electricity to charge your devices.