The latest project I worked on in college is a calculator created using TDD (Test Driven Development). It’s based on a project taken from Google’s Testing Blog located here. It’s a fully functioning calculator similar to the one available with Windows.
I’ve added it to a .jar file which you can download below and run by double-clicking it like a normal application after extracting it from the .zip archive. Extracting the .jar file afterwards will show you my source code.