It ?s true: you can build native apps for iOS, Android, and Windows Phone with C# and the .NET Framework ?with help from MonoTouch and Mono for Android. This hands-on guide shows you how to reuse one codebase across all three platforms by combining the business logic layer of your C# app with separate, fully native UIs. It ?s an ideal marriage of platform-specific development and the "write once, run everywhere" philosophy. By building a series of simple applications, you ?ll experience the advantages of using .NET in mobile development and learn how to write complete apps that access the unique features of today ?s three most important mobile platforms. Learn the building blocks for building applications on iOS, Android, and Windows Phone Discover how the Mono tools interact with iOS and Android Use several techniques and patterns for maximizing non-UI code reuse Determine how much functionality can go into the shared business logic layer Connect to external resources with .NET ?s rich networking stack Read and write data using each platform ?s filesystem and local database Create apps to explore the platforms ? location and mapping capabilities