To make android app like SoloLearn what I have to learn or know?

Question

I want to make android app like SoloLearn. 😉
But I don't know exactly what should I have to learn besides Java. 🙁
So, if you have the knowledge about it, please share......🌼
Don't leave away without commenting... ;)
All the answers are welcomed.........🌼🌼

Answer 1

It's possible to make JavaScript apps ( • •)
But indeed, SoloLearn has been created in Java

Answer 2

Use Android Studio to make Android apps with Java.