Book excerpt: The creation of apps for Apple's iPhone is now a huge, and global business, with hundreds of thousands of developers, entrepreneurs and companies attracted by the potential rewards. But games, functional apps and promotional apps alike depend on attractive, intuitive design for their appeal, and most fail to find a significant audience. With this book, you'll be able to turn your great app idea into a functioning design that is ready for coding, or apply graphic design skills to this exciting and lucrative marketplace. You will have a clearly visualised concept and a focused sales plan - and your app will stand out in an App Store that is worth well over a billion pounds every year.