I recently purchased this amazing game that makes you think in three dimensions and tests your spatial skills. You start with a scattered mess of dots, dashes and shapes on a blueprint. By rotating these images in three dimensions, you gradually make sense of the chaos and discover the image before you. http://itunes.apple.com/us/app/blueprint-3d/id456244246?mt=8 There are over 240 levels. You can even purchase solutions packs if you get really stumped. This is really worth checking out!