Why didnt you design the app to function with all versions of the iPad?
I can not down load for my version of the iPad I own. In order to use your product I would need to purchase a new iPad.
Please put verbiage on your site and in the App Store for what version iPads the app is comparable with.
The App Store page for OrthoGraph I does contain a list of devices that the app is compatible with. There is a compatibility entry in the information section both on the iPad and web versions of the App Store.
Are you having problems running OrthoGraph on any of the device listed in that compatibility list?