May 21, 2016
1.1 Add "How many squares in a 16x16 grid-square?"
1.2 Add ancient Chinese solution to 3x3 magic square.
1.3 add 15-puzzle slide game
1.4 now you can play YPK software's 15-puzzle slide game
1.5 add Duler Magic Square, and use it as a base for sliding games.
1.6 add hint to 15-puzzle slide game