Secret is a newish free iPhone app that lets you share messages with the contacts in your phone anonymouslyish. I say anonymouslyish because although there are no profiles or names attached to posts, it's possible to figure out who might've sent the message by teaming up with people with friends in common and knowing your friends' schedules and posting habits, or in other words, using process of elimination. But for the most part, it's incognito fun.
Secret also allows you to pick a color or an image for a background as well as comment on other people's secrets (also anonymously). Sure, some people are dicks like my friend who posted a House of Cards spoiler Saturday night, but this app has the potential to be pretty amusing. My advice? I know the folks behind Secret say you can use it say your mood and share pictures, but it works better when what you post is actually a secret, ya know something everyone doesn't already freaking know. Oh, and not a massive spoiler, you jerks.