I'd like to create an iPhone app that supports tracing of arbitrary shapes using your finger (with accuracy detection). I have seen references to an Apple sample app called "GestureMatch" that supposedly implemented exactly that, but it was removed from the SDK at some point and I cannot find the source anywhere via Google. Does anyone know of a current official sample that demonstrates tracing like this? Or any solid suggestions on other resources to look at? I've done some iPhone programming, but not really anything with the graphics API's or custom handling of touch gestures, so I'm not sure where to start.