- I really like the flowchart arrangement. Great idea for a top-level organization scheme! I like the way things branch out but then come back together for regularly spaced "Check points".
- Everything seems to work really well on mobile. Nice!
- There doesn't seem to be a general way to progress on to the next lesson at the bottom of each topic page. Am I missing something? Or is it your intention to have students return to the flowchart between every lesson? If so, it would be nice to have a button that just goes there (and, I would imagine, scrolls down the flowchart page to their last accessed lesson). "Back" does go to the Flow page IF that's where you immediately navigated from, but in the first two pages you actually progress on to the next lesson by clicking a link—so "Back" goes back to that page, not up to the flowchart page.
- I'm not sure about the UI/UX decision of your "Incomplete"/"Complete" indicator at the bottom of each lesson. It's odd to have a greyed out button that says "Incomplete" that changes to filled in and the word "Complete" when clicked/tapped. Also, the "Back" button looks exactly the same, but is a navigation button, not an updating status indicator. So there's some conflation of different functions with the same form there—could be confusing. The "Bookmark" button is fairly clear, but the word "Incomplete" all by itself with no other explanations does not convey very clearly to me that I'm supposed to click on it in order to mark the lesson complete (I figured that out by trial and error). Maybe try "Complete" and "Completed" to match your "Bookmark" and "Bookmarked" in the other button?