Before QuizUp became one of the most popular iPhone services, it was a floundering series of one-off apps developed by startup Plain Vanilla Games under the name "Global Trivia Project." The apps were a sort of Trivial Pursuit for your smartphone: There was a QuizUp app for basketball, for math, and so forth. But it wasn't until the startup launched its Twilight app that the team knew it had struck a chord. "Players were just going insane--there was one guy in Italy who had 20,000 wins," recalls chief design officer Sveinn Davidsson. "We realized then that people can get very crazy about trivia--and it actually guaranteed us most of our funding."
Even then, the Twilight app featured many of the elements that makes QuizUp so popular today. Along with its ranking system and crowdsourced question database, the app featured one-on-one timed match-ups, allowing users to compete with each other in real time.