You're probably seeing the old Problem Sets when you hit "Continue". We recently added in new ones, but the old ones are still available here:
http://7sage.com/lesson/old-problem-sets/
@petitigre We changed the site so now you can now use left and right arrows to go to the next/previous lesson/explanation. You may need to use a force refresh to see the changes.
There's also a full section in the curriculum available to both paid and free users you can check out here:
http://7sage.com/lesson/the-blind-review-is-a-habit/