What programming language are you currently mainly working with?

Currently, the programming language predominantly used for Android app development is Kotlin. It is officially supported by Google and offers modern features that simplify development and enhance code safety.

Previously, Java was widely used, but now Kotlin is considered more preferable due to its conciseness and improved support for functional programming.

An example of a simple class in Kotlin:

class Greeting {
    fun greet(name: String): String {
        return "Hello, $name!"
    }
}

Therefore, if you are starting or developing a career as an Android developer, it is advisable to focus on Kotlin.