A free app for Android, by Dive-In Creation.
This is a free puzzle game that lets you train your brain with number puzzles. You have to slide the blocks to their right place. Slide the block to the right position, to the left or up. You can only move one square at a time. You can only move one square to the right or to the left, and you have to make sure that you don't move a square into an occupied position.
You can play with one or two players on a single phone. The AI is very smart, and the puzzles are designed for two players. You can play with friends or family, and you can play at your own pace.
The AI is 3 levels of difficulty. It's easy, medium and hard. The more difficult the difficulty level, the more points you can get.