Khan Academy is a great place to start. With their learning web of what math leads to what math, videos, and quizzes it is a nice package. It presents fairly well on the iPad, but you watch the videos through their app and have to find the matching quizzes on the website.
The DragonBox app is a nice way to rapidly ramp up alegraic manipulation skills.
Downloading math apps has been an obsession in our house the last couple of months.
Does he have a preferred mode of learning? (does he like videos with people, videos with equations, hands on practice, reading and practice, etc.)
