Thank you. I did not know readlang, but my project is different because I want to customize the help given depending on the user.

Also, I plan to focus on the challenges inherent to Japanese rather than extending my tool to other languages. The Japanese grammar being simple and regular, I am quite optimistic that I can show help about it without relying on raw translations. One challenge of Japanese is that a raw translation does not help to learn the readings/pronunciation and Kanjis, so it is in my experience almost completely useless for learning.

I also do not want to provide contents. I want the user to choose whatever he likes on internet (but I may recommend external interesting pages).