15 puzzle CHALLENGE

This is the first 15 puzzle in which you can challenge your friend with the same combination of numbers that you solved! Once you have solved the puzzle in "Classic" mode click on the "Challenge a Friend" button! Do you think to be the faster to solve this puzzle? It's also called Slide Puzzle, Block puzzle, Gem Puzzle, Boss Puzzle, Mystic Square, Brain Puzzle, 15 Solitaire.