Ask HN: Startup ideas for the mobile App developer market?

I read that there are 8.7M of app developers worldwide. I don't know if that's accurate but probably there are way more than 500K developers. That's a huge market, which also is highly technical and value software tools. There should be a lot of products to build. I would like to know your thoughts and ideas.

There are some threads out there, but not so accurate to this very specific topic: https://www.reddit.com/r/SomebodyMakeThis/ https://news.ycombinator.com/item?id=10320865