FDG Entertainment's Blueprint 3D [$0.99 / $1.99 (HD)] is one of those perfect mobile games that you can describe in a single sentence to make it appeal to just about everyone. In a nutshell, you manipulate drawings in 3D space and try to rotate them in to being what they should be. It sounds easy, but can be stupidly difficult particularly in later levels when the drawings get really complex.
You can see this all in motion towards the end of the trailer they released back when the game first hit the App Store:
We posted a review of the game way back when, and enjoyed it quite a bit. I'm not sure what other coaxing I can provide to download a free game, so, get to it.