Android is an operating system that is in use in many types of mobile phones, tablets, and other devices.

Traditionally, Android applications are developed with the Java programming language, and the user interfaces of Android apps are specified with XML. Nowadays you can use the Kotlin programming language in place of Java.

Google recommends that Android apps should be developed with a new toolkit named Jetpack Compose. With Compose you make Android apps without XML and only in Kotlin.

Here are some links that should be useful when you learn to develop applications (apps) for Android-based devices.

Some of the Android apps that you can find through the links above are just single files. Please, read the comments at the beginning of the files to find out how you should create the actual projects in Android Studio.

Some Android videos in English: