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.