Puzzle 15

The 15-puzzle (also called Gem Puzzle, Boss Puzzle, Game of Fifteen, Mystic Square and many others) is a sliding puzzle that consists of a frame of numbered square tiles in random order with one tile missing.

The object of the puzzle is to place the tiles in order by making sliding moves that use the empty space.

If you think it's easy, try it without displaying the numbers or without removing your finger from the screen