Get Lorenz Attractor in the App Store
The Lorenz attractor is a solution to the system of coupled differential equations
The visualization starts at a random point with each update, but no matter where the curve starts it has the same overall shape. This the essence of a mathematical attractor.
Try varying the parameters to see what effect they have on the curve. Some combinations of parameters will destroy the attractor, and you may need to zoom out by pinching or rotate by swiping to see the resulting curve.