With the iPad I was finally able to create a multitouch roller coaster track editor that is truly usable. Trying to create a roller coaster on a tiny iPhone screen never really felt right. In AirCoaster XL you can navigate around your track using 1 finger to rotate, 2 to zoom and 3 to pan. Tweak and adjust any segment in the track by tapping on the segment to select it and then dragging the manipulator tools (the colored 3D arrows) to get it to look the way you want. Check out the screenshots. Gotta love the 1024x768 screen resolution.