With the proliferation of smartphones and tablets, apps have taken the world by storm and captured the collective imagination. They range in nature from delightfully frivolous and whimsical to sturdily practical and utilitarian, simple and straightforward to dazzlingly elaborate. In an incredibly brief period of time, they have become fundamental to the smooth and pleasurable functioning of most people's daily lives. App designers are the new rock stars of the programming world. Any teen seeking to learn what apps are, how they work, and how they can be designed, programmed, tested, and sold to the highest bidder will find all these questions answered in these pages. This hands-on, how-to resource packed with practical insider information is sure to help launch many of the next great apps soon to be downloaded to mobile devices. Its emphasis on career-building, science, and digital literacy content fully satisfies Reading Anchor Standard 10 of the Common Core Curriculum.