As the developper of the educational software GCompris ( http://gcompris.net/ ), I am glad to see how far they went in their project. Just looked at their documentation and it is really impressive. It is really motivating for free software developpers to see our work is useful.
That's sad they did nothing inovative here. They use the classic matching pair over and over again. There is a lot of thinks a software can be usefull to help children.
I can continue working on the educational software GCompris.