Getting the entire development environment working took some doing. For information about the challenges I encountered in getting the Processing 2 Android development environment up and running on my Windows laptop, see my blog post A Simple Android Processing Painting Sketch.
Update 03/26/16: For Processing users interested in developing on a Linux platform, I have written the following tutorial specifically for the Ubuntu Linux distribution: Installing Processing 3.x on Ubuntu Linux Systems Tutorial.
Processing Oscillating Ellipses Animated Painting - my first Processing.js sketch created 6/22/2013.
Party Lines - featuring dancing lines and audio is an independent homework project for the Creative Programming for Digital Media & Mobile Apps class. Sketch published 6/30/2013. Modified 7/3/2013 to add a basic GUI interface.
Party Lines Sequel - featuring dancing lines, curves, ellipses, and audio is an independent homework project for the Creative Programming for Digital Media & Mobile Apps class. Sketch published 7/16/2013.
Simple Picture Painter - is a simple picture painter that uses a source photograph to determine what colors to draw. This sketch was the final project for the Coursera Introduction to Computational Arts: Processing class. Sketch published 2/27/2014.
I am providing the following links as a courtesy to those who would like to learn more about Processing and Processing.js and perhaps create their own sketches.