Learn how to add default and static methods to your interfaces, create repeating annotations, and use lambda expressions and method references.

The RRO framework lets you create themes that change the look of almost every app on an Android device. Learn how to use it to edit the quick settings tray.

Lambda expressions can help you process huge amounts of data with ease. See how with this in-depth look at Java 8 features you can use in Android projects.

Android app templates are a huge time saver. We've combed through thousands of Android app templates available at CodeCanyon to find the 15 best available.

Get an introduction to object-oriented programming in Kotlin by learning about classes: constructors and properties, casting, and advanced class features.

Learn how to to achieve concurrency in RxJava with Schedulers, the subscribeOn() operator, the observeOn() operator, and the flatMap() operator.

Kotlin is a functional language, and in this post, you'll learn about extension functions, higher-order functions, closures, and inline functions in Kotlin.

Learn about top-level functions, lambda expressions, anonymous functions, local functions, infix functions, and member functions in Kotlin.

In this tutorial, we'll start by looking at how to organize code using packages in Kotlin, and then go on to an introduction to functions in Kotlin.

If you are a mobile app developer or interested in getting into designing apps and you haven’t heard of Envato Elements, this post is for you.

Kotlin is free and open source, and makes coding for Android more fun. In this tutorial we'll look at advanced data types such as ranges and collections.

Learn how to add a feature module to your instant app, and then discover how to get your finished instant app project into the Google Play store.