ViewTube

Java: 

Java was the original and primary language for Android development. It provides a robust and platform-independent environment through the Java Virtual Machine (JVM). Many Android applications have been built using Java.

Kotlin:
Kotlin is a modern programming language developed by JetBrains. It gained official support from Google as a first-class language for Android development in 2017. Kotlin is designed to be fully interoperable with Java, making it easy for developers to migrate from Java to Kotlin. 

XML (Extensible Markup Language):
While not a programming language, XML is extensively used in Android development for designing layouts and defining UI elements. Android uses XML for defining the structure and appearance of user interfaces.  

C/C++:
For performance-intensive tasks, Android developers may use C or C++ languages, especially when working with the Android NDK (Native Development Kit). 

Thanks ..