Do you like all things trivia? Then you'll love QuizUp, which is being hailed as the "fastest-growing iPhone game in history."

The trivia game amassed 3.5 million registered users within 3 weeks. By the eighth day, it reached its 1 millionth user (in comparison, 2012's Draw Something took about nine days to reach 1 million users).

QuizUp is a free trivia game for iOS that offers more than 150,000 trivia questions in about 300 categories. Each quiz has seven rounds that lest ten seconds each. You can challenge both your friends and strangers to see whose IQ reigns supreme. Guess it's a fresh change from spending hours of your life crushing candy all day...