My Windows Runtime via C# book originally targeted developers building Windows Store. However, with the introduction of Visual Studio’s universal apps, the book is now applicable to Windows Phone 8.1 app developers as well. So, Maarten and I have created a document that goes through chapter by chapter explaining the few places where the book’s contents differs for Windows Phone apps. In addition, I have ported all the book’s sample apps to be universal apps; this allows them to build and run as both Windows Store apps and Windows Phone apps. To download the document and the new new code click here, scroll down to the entry for Windows Runtime via C# and select “For Windows Phone Developers” to download the document or select “Source Code” to download the new source code.