I'm a big fan! Such a fun way to approach a new language! Would make it absolutely perfect (in my mind) if you could click the hiragana to hear the sounds, but I understand that that would require a lot of storage.
Thanks for the kind word. It's not the first time I have been suggested to add some audio. I am not against the idea but I'd rather focus my time on creating content. Also I believe some browser extensions such as this one can do it https://chrome.google.com/webstore/detail/rikaikun/jipdnfibh...
(For my self, I'd made this one-word-a-day tool https://dugas.ch/word_of_the_day/)