Sounds like Khan Academy's knowledge map: https://www.khanacademy.org/exercisedashboard https://www.khanacademy.org/exercisedashboard I think you have to be l

Sounds like Khan Academy's knowledge map: https://www.khanacademy.org/exercisedashboard https://www.khanacademy.org/exercisedashboard I think you have to be logged in, but you can see a screenshot here: http://i.imgur.com/3HyRRyv.png http://i.imgur.com/3HyRRyv.png