I think the main problem for OP are competing tools like Duolingo - Maybe he should try to get in touch with them to see if his product could be complementary t

I think the main problem for OP are competing tools like Duolingo - Maybe he should try to get in touch with them to see if his product could be complementary to their offering (and work with them)? This is a long shot but maybe the attention from HN could be enough ammunition to get a conversation started. I think duolingo also shares OP's philosophy of focusing on regular users as opposed to businesses.