Connect Four is a classic game. I have used this connect four board that I created for the bases of numerous review activities/games in my classroom. The game is quite simple. Once a team answers a question correctly, they get to choose which square to place their color. All you have to do as the teacher is click on the color of the little dot inside of that square and the square will turn that color. It's easily modifiable and the simplicity of using technology and a powerpoint on a projector really gets the kids involved.