TouchDraw

TouchDraw is a vector drawing application that gives you everything you need to create structured 2D vector graphics such as flow charts, graphs, diagrams, illustrations, logos and floor plans just to name a few. What makes TouchDraw especially valuable is that it allows you to not only create complex graphics, but to change them easily as well.

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 it's shape, change it's color, group it, without affecting other shapes that are around around.