In the previous chapter, we took a concise look at crucial topics pertaining to the core Kotlin language. These topics took us through the fundamentals of Kotlin as well as the powerful object-oriented programming approach to software development it puts at our disposal. In this chapter, we will put the knowledge we gained from the previous chapter to good use by developing an Android application.

In this chapter, you will learn about the following topics:

• Android application components
• Views
• View groups
• Layout constraints
• Implementing layouts with XML
• String and dimension resources
• Handling input events

We will learn these topics through a hands-on approach by implementing the layouts and components of a classic game, Tetris, in the form of an Android application. As we are developing the game in the form of an Android application, before proceeding further, it is imperative that we do a brief overview of the Android operating system.