I would like (in the distant future) to teach statistics to kids. For that matter, I'd be happy to know of software (obviously I am tending towards FOSS), or webapps, that are helpful in explaining statistical/probabilistic ideas to kids (or adults for that matter).
This can be used either by the instructor, the kids, or both.
Suggested format of the answer: Software name, what it help teach, who should use it, link.
Best Answer
Videos and animations from Understanding Uncertainty website.