This book is a comprehensive guide to building Android applications using Android Studio Narwhal (2025.1.1), Jetpack Compose, and the Kotlin programming language. It is designed to provide the knowledge and skills you need to create modern Android apps using the latest development tools and frameworks. We begin with foundational steps, including setting up an Android Studio development environment, followed by a detailed introduction to Kotlin, the language underpinning Android development. This section covers core aspects of Kotlin, including data types, operators, control flow, functions, lambdas, and coroutines, establishing a solid foundation in object-oriented programming principles. Next, we cover Jetpack Compose, Google's innovative toolkit for building native user interfaces, including an in-depth look at Compose components and layout structures, including rows, columns, boxes, flows, pagers, and lists. You'll also gain insights into Android project architecture and Android Studio's Compose development mode. Advanced topics are also covered, including state management, modifiers, and UI navigation. You will also learn how to create reusable layout components, implement biometric authentication for enhanced security, and accelerate development with Gemini AI. The guide also covers specialized techniques, including graphics rendering, animations, transitions, Kotlin Flows, and gesture handling. Practical data management solutions, including view models, Room database access, live data, and the Database Inspector, are explored in detail. For developers interested in monetization, this guide also includes a dedicated section on implementing in-app billing. The concluding chapters provide a comprehensive overview of app packaging and the publication process on the Google Play Store. Throughout the book, each concept is reinforced with hands-on tutorials and downloadable source code. Additionally, over 50 online quizzes are available to test your knowledge and understanding.