Ray Cromwell and the Timepedia team have released Chronoscope, a charting and visualization platform for Google Web Toolkit, as open source.

When Android came out, they quickly realized that the same charting library that is written in the Java programming language, compiled to JavaScript, could also work on other platforms. So, they tried to get it working on Android:

It required about 8 hours to get this working. Most of the time was spent finding the Android equivalents of Java2D calls, and writing 6 Java classes (the Chronoscope Canvas abstraction layered over Android Graphics API).