Hello,
Thanks a lot for your job, this app is wonderful with the spirit you giving it.
I've loved to discover the addings I saw, like the possibility to see the map with the NO², or PM2,5 filters. By sawing it, I asked myself what is it and how it work ? Then the idea comed to me that it could have a link on the filter's buttun to a page with the answers at the questions.
I imagine that is it a lot of work but it's maybe possible to directly send on a wikipédia page.
Wish you the best.
Ino