I co-created Albatross with my coworker Changbai. Albatross (our internal projects are always named after birds) is an experimental collaborative game that simply requires a monitor and the participants' phones.
Participants enter a URL (specified on the large screen) into their phone's web browser to be directed to the intro screen. The premise of the game is to choose one of two teams (our example was purple or cyan, but depending on the event, they could be two sports teams, two pop culture references, etc) and tap your screen as quickly as possible to strengthen your team's color block and push it to the edge of the large screen. The ideal use case would be to entertain crowds before concerts or keynote presentations.
To keep the players on their toes, we periodically unlocked their phones' accelerometers. Player had to pay attention to both the large screen to track their team's progress, and their phone screens to stay on top of challenges.
If we were to develop this project further, I think it would be fun to add more complex variations of tapping challenges beyond the basic accelerometer unlock. Things like evolving team zones, accelerometer-based mazes would add an additional element of crowd excitement, especially if it was used on a much larger scale.