Michael Sayman, originally invited to Facebook as a 17-year-old by Mark Zuckerberg, created a video-centric social app for teens, Lifestage, when he was 19. Now the young superstar is behind a secret Google social-gaming startup called Arcade, according to a report at Bloomberg. The new company's first app, say the site's sources, is set to debut this summer with elements of trivia games at its core.