Marie Van Belleghem,
People who like music often enjoy guessing the artist of a song. When they are waiting in line for an event, they can now play bingo-like game on their phone which allows them to do just that. You can even choose to sing along as parts of the songs are playing and the lyrics appear on the screen. You can participate no matter where you are in the line and you can even keep guessing without playing on your phone. It keeps people from getting bored whilst in line and they can choose for themselves how to participate. Even when they do not actively participate, they have something to look at and listen to.