It is a sliding puzzle that consists of a frame 4×4 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. Use long press to exit from application. It's smallest (only 15k) and ads free Puzzle 15 app ! This is 2in1 version ! You installing the game on your mobile phone and get two identical working games: one on your mobile phone and one on your smartwatch. It working on all devices with all screen resolution, including Wear OS smartwatch (round and square) ! If you like this app please do not forget to give a positive feedback !!! Recently the rating this app fell 100% anonymously from 4.8 to 3.5 :-(