Sticky Numbers description

Sticky Numbers is a simple logical game.
Your task is to fill the board with number 0.
When you click on the button, number on that button is subtracted by one.
Same thing happens to the surrounding buttons in all four directions (top, bottom, left and right). If the number is 0, then it goes back to 3.

Buttons on right :
Next - New game
Back - Undo last move
Exit - Exit the game

Have fun!