Nim's Game

Nim is a game of strategy in which players take turns removing marbles from distinct piles. In the traditional version of the game, you may take at least one and up to 3 marbles from any single pile. Whoever takes the last marble wins the game. You can play with up to 3 piles, but you may only take from one pile at a time.
Another variation of the game allows you to take from multiple piles in the same turn, as long as you take the same amount of marbles from each pile.
This app supports single player and two player. For single player, you can select from a wide range of difficulties from beginner to master. You can specify the number of piles you want to play with and the maximum number of marbles that each pile can start with. This app also supports both versions of game play mentioned above.
You can also track your stats, and there is a full table that shows your winning percentages against various difficulties. When you defeat a difficult opponent, your skill level will increase, but when you lose, your skill level will decrease.