Big news! Grey Matters has just released its first iPhone/iPod Touch app on the iTunes App Store! The App is a puzzle/game called Knight's Tour+ (iTunes Link), and is available for only 99 cents.
Knight's Tour+ is both a challenge on its own, and a great way to practice the Knight's Tour solving techniques I teach in the Mental Gym.
For those unfamiliar with the Knight's Tour, it takes place on a chessboard, using only a single chess knight. The knight can only move in the standard L-shaped move (two squares vertically and one square horizontally, or two squares horizontally and one square vertically). For example, from the square where the knight is shown below, the only possible moves are to the squares marked with Xs:
The basic challenge of the Knight's Tour is to land on all 64 squares without ever moving to any square more than once.
However, this challenge is only the first level in the Knight's Tour+ app. A screenshot from Level 1 is shown below:
The squares marked in blue are ones the Knight has already visited, and cannot be revisited. The left pointing arrow are the bottom allows you to take back a move, in case you make a mistake. You can actually take back all your moves one at a time by this method, or use the rewind arrow (left arrow with a line in front of it), to immediately restart the same game.
The i button takes you to where you can find more information, including the rules, interface usage, credits, and a link to the Mental Gym's Knight's Tour lessons.
The New Game button at the bottom will start a new game by offering you a choice of levels. We've already seen Level 1, but what are the other 2 levels?
Level 2 is called End Where You Began. Once you make your first move, a house icon appears on your starting square, as in the following screenshot:
After you've finished landing on all 64 squares, the additional challenge in Level 2 is to be on a square that's only 1 knight's move away from this home icon.
The final level is Level 3, called Random Start & End. Your iPhone or iPod Touch chooses not only a random starting point, but a random ending point, marked by a bullseye icon. The challenge here is to finish on the bullseye square after landing on all of the other squares.
Whether you just want a new challenge, or learn how to do the Knight's Tour and be able to practice on the go, you can download Knight's Tour+ (iTunes Link) for only 99 cents and start today!