TouchDraw™ for iPad
TouchDraw for iPad is a powerful, yet easy to use, vector 2D drawing and diagramming application for iPad. It has many of the features of desktop applications wrapped up in a mobile package. Best of all, it's only a fraction of the price of a desktop application.
TouchDraw for iPad is fully compatible with TouchDraw for Mac and TouchDraw for Android and files can be freely exchanged between all three versions. TouchDraw differs from a paint program in that objects are always managed independently of the drawing they're in. You can move a figure around, change its shape, change its color, group it, without affecting other shapes that are around it.