How does that compare to Khan Academy?

How it's similar:

- focused on mastery

- good treatment of math

How it's different:

- doesn't cover elementary school topics

- lessons are text, not video

- paid, not free

- lessons are presented based on what you already know (e.g. you can't choose to study a topic before you've demonstrated mastery of all topics it depends on)

- I pick the next lesson from a very small set (usually 5 options, sometimes fewer), so there's no wasting time choosing what to study next

- really great spaced repetition system that prevents forgetting

Thanks for the head’s up.

$50/month is pretty steep for what looks like a Khan clone.

It is accredited though. College credit?

They don't grant degrees or diplomas. As such it is presumably accredited as a Supplementary Education Program and (like JHU CTY, Stanford ULO, and AoPS) do not grant credit. Such programs can be the basis of credits if your "real" high school accepts them, though.

Right, ymmv for transfers at either a hs or college. But the accredited status makes it possible to get approval. MA say they can make the documentation available manually and will automatically in the future.