Might be nice to make the quiz easier to find on the main page. It took me some scrolling and looking before I saw it, and, and maybe make it accessible without creating a user account. I'd definitely do the free quiz, but seeing a sign in screen so early on is kind of off putting.
That makes sense, I do need to calibrate and store recorded words for the user in the database after that. Do you think a user would be more off put after taking the time to do a quiz, to then realize they need to create an account?