What IT courses on mobile development to choose?

Question

Android

Faced a learning problem.
Given:

• Web developer, about 3-4 years;
  
• Pathetic attempts to approach Kotlin and Swift;
  

I realized that I need to buy / sign up for courses on mobile development.
Question: what courses would you recommend specifically for android, ios development (MB taught themselves)?

Answer 1

None. Well, the "attacker" who receives a penny will not teach you something worthwhile.
Read books.
This is the answer.

Answer 2

On Android, tons of information on the Internet is freely available. Courses are not needed now.