DifferenceEqLab

Also available: FunctionLab for graphing functions of a single variable.
To download the DifferenceEqLab application to your computer, click here:
download DifferenceEqLab.jar
or use ftp to access
ftp://www.myphysicslab.com/graphlab/build/DifferenceEqLab.jar

By running locally on your computer, the copy buttons should work.

Documentation on the open-source code is available.