"Mind reading" program. The user inputs a string of 0s and 1s and the computer guesses what they will input next based off their previous input. If the computer guesses correctly, it gets a point. If it guesses incorrectly the user gets a point.
The best strategy is to avoid falling into any patterns. If you enter 0s and 1s randomly the algorithm will not be able to predict what you are going to next.
The game is implemented in both javascript and python. You can play the javascript version online at http://success-equation.com/mind_reader.html