This app was removed from the App Store.
iOS iPad Education
Set of 10 unbelievable CALIFORNIA historic panoramic views. Check how cities looked like before. Everything in extreme resolution up to 500megapixels. Perfect XIX century drawings on iPad with 2500% zoom - let you study all details created by lithographers.
appadvice.com: "the level of detail, high resolution, and “zoomability” of the maps in this app can’t so easily be found elsewhere."