Orbit Architect App for iPad
'Orbit Architect allows you to interactively design and explore satellite orbital geometry through the multi-touch interface of the iPad. You can manipulate a satellite orbit using pinch and rotate multi-touch gestures, see the effects on the orbit and its ground track in real-time, and animate the results. As you change the orbit, dynamic diagrams will illuminate the meaning of each orbital parameter. Finally, the results can then be emailed to yourself or to a friend.'
This is a free app.