Open Source Handbook "A manager's guide to the business and organisational applications of open source technologies"

App: GLGestureRecognizer

This is gesture recognition algorithm which is an implementation of the $1 Unistroke Recognizer that has been written in Objective-C for the iPhone. The software receives touch events and makes a best-guess match to a human gesture. It was released in 2009 by Adam Preble as open source - with the sole condition that those using the app email him with details.

Resource: github.com