Because you forget so much of what you dream almost instantly, at some point in your life you've probably thought it would be a worthwhile pursuit to maintain a journal full of your crazy shut-eye antics. Shadow ($8) takes the idea of a dream journal, and expands on it, making it into a smartphone app. It's part alarm clock, part dream journal, and part cloud-connected application, letting you record your dreams as you wake up, either by voice or text. But, Shadow has loftier ambitions than being just another dream journal. After you record your dreams, certain keywords and data about your dreams are added anonymously to a database, collecting information from a yet-untapped datasource: our collective subconscious.