The average NFL game last 3 hours. How much of that involves actual play? Just over 12 minutes.
That leaves a lot of time for fans to kill between plays. NFL Playbook is a real time app which allows the crowd and at-home users to guess the next play on the field before it happens.
Run or pass? Completion or incompletion? How many yards gained? Field goals and PATs made or missed? These are all options for the user, casual fan and diehard alike.
Correct answers are worth points which the app saves game-to-game and week-to-week. Top players win prizes each week and at the end of the season, which means there's an incentive to keep playing.