This is a classic two players game redeveloped for iPad based on 4_IN_1_ROW powered by Mathematicians. If you want to become a Connect Four killer, please play this game. In the application, we used the latest research result and mathematics engine provided by Mathematics to improve the thinking power of iPad. Features: 1, Bluetooth supported, you can play with the neighbor device(including iPhone which installed the pro version of this game) in human to human mode. 2, Play mode: human to human, human to device, device to device. Touch the iPad image button or human head button in the top left/right of the screen to select play mode you like. 3, Sound on/off. 4, Undo: you can undo all the steps. 5, Difficulty: easy, medium, hard. How to play with the neighbor device through bluetooth connection: 1) Start this app. 2) Set play mode to human to human. 3) Touch the bluetooth image button on the right bottom of the screen, and select player. 4) After finishing connection with other device, touch NEW GAME BUTTON(two balls) to start.