I want to know the courses I should learn here to become an app developer?

Question

Android

Answer 1

Java, and then:
https://developer.android.com/studio/index.html

Answer 2

@Abdul: Check this link to know about courses and resources for app development:
https://www.sololearn.com/Discuss/242006/for-all-budding-app-developers-here-are-some-useful-links-for-you

If you are interested in game development then visit this link:
https://www.sololearn.com/Discuss/241201/for-all-aspiring-game-developers-visit-this-link