Monument Valley by UsTwo is quite possible the app of the year! Amazing! $3.99 on iTunes
Monument Valley, UT and AZ the vast expanses of the American Southwest. Hundreds of miles from any major metropolitan area, the sandstone buttes at Monument Valley Navajo Tribal Park rise majestically from the earth's surface
Mind-Bending iPad App Channels M.C. Escher - challenge students to thing abstractly.