A free app for Android, by Happy Bubble Games.

Stack Sort Puzzle is a fun and addictive puzzle game! It will keep you hooked for hours. In this game, you are trying to move the stack of donuts by using the spool. There are some blocks that you need to move to make room for new blocks. Each level has an end. The challenge is to move the blocks in order to reach the end of the level.

It is a casual game, so you can play it anytime, anywhere. It is easy to play and has simple rules. You can play with friends or family and enjoy it together.