Thanks for these useful sources. I'm not a professional, but I study hard to become a better app developer. I like this article https://madappgang.com/blog/healthcare-app-development-how-to-build-a-helpful-medical-app about medical app development. I found there a lot of useful things and hacks.

If you need a professional company, I have a recommendation for you. I worked with this mobile app development company at https://madappgang.com/platforms/kotlin cause they are the best developers who use Kotlin. It was quite cheap and the quality was on the top lvl.