Yo | TechCrunchYo. It seems so simple. So mindless. It’s only slightly less boring than “Hey” or “Hi,” if only because of some perceived aggression or excitement attached to it. But Yo is anything but simple. If you haven’t been following along on Twitter, Yo is the hottest new app that will leave you scratching your head. The entire premise of the app is to send other users a single word: Yo. Yo currently has o
