A100 is the Iphone version of an old school game, originally played on the math exercise bookYou play on a square field composed by 100 Balls; your target is clear all balls from the squareYou clear a ball by simply "Touching" on itYou can start touching by any ball on the field, then you can touch balls using these rules you can jump two balls left or right (and "touch" the third)you can jump two balls up or down (and "touch" the third)you can jump one ball diagonally (and "touch" the third) There are 10 levels, you advance to the next by clearing at least the minimum number of balls of current level.Enjoy !!