A knight's tour is a sequence of moves of a knight on a chessboard such that the knight visits every square only once. If the knight ends on a square that is one knight's move from the beginning square (so that it could tour the board again immediately, following the same path), the tour is closed, otherwise it is open.
This was an early project I developed when I was super enthusiastic about making an app for everything I learn. We solved the Knight's tour problem in our data structure's class and I thought making a game out of it would be really fun. The aim is to cover an entire chess board using just your knight. The code is general enough to allow grids of varying sizes.