This book is a second and companion text to Harrison's original volume, Symbian OS C++ for Mobile Phones (SCMP), published in 2003. It will only briefly cover in an early, introductory chapter Symbian OS fundamentals, such as error handling, object creation and destruction, descriptors and active objects.  Thereafter it will describe those new features particular to V7.0 (s) and it will provide conceptual and theoretical underpinnings of the OS to give developers a thorough understanding of Symbian OS. Its central approach will be to describe the interaction between the OS and the application, broadly following the lifecycle of an application. At each stage of the lifecycle for example, on application startup it will describe what actions take place in the OS, what the system does for the application and what the system expects the application to do.  With plenty of code examples, the book will detail advanced features such as user interfaces, files and views, multimedia services and communications and messaging. In contrast to other available and forthcoming titles, its central approach describes the interaction between the OS and the application, broadly following the lifecycle of an application. At each stage of the lifecycle for example, on application startup it will describe what actions take place in the OS, what the system does for the application and what the system expects the application to do. The book covers aspects of Symbian OS not available in v7.0 (SCMP), which are introduced by Symbian OS v7.0s.