In my book, Tap Move Shake, I discuss in great detail the proper way to handle multitouch and issues that come up when implementing head-to-head play. To explore these issues, I created an app that demonstrates how to draw circles around all the touch points that an iOS device has on the screen. It’s a good sample program to not only demonstrate the issues of head-to-head play pointed out in the book, but works as a good lesson in how to implement multi-touch in your programs.
Download Touches Source Code – Universal app for iPhone and iPad which draws circles around every touch point received by the device.