Could be very useful for people learning a new language! (consider marketing to language learning subreddits / communities).
I would find it useful for that exact purpose, however, I think 500 words might be too much. 150-200 is good enough. Would be cool to be able to change the amount of words required.
It would be interesting to combine the daily routine concept, with an AI chat engine, so the goal is to have daily conversations of a certain length/depth, about random topics, between you and an AI, in your target language.
I would find it useful for that exact purpose, however, I think 500 words might be too much. 150-200 is good enough. Would be cool to be able to change the amount of words required.