iPhone Web Apps make for an incredible iPhone user experience—no software installation necessary.
iPhone applications come in two varieties: The first are true software applications that are downloaded through the Apple App store—commonly referred to as iPhone apps. The second type of iPhone app is a Web-based internet application that any iPhone/iPod Touch user can navigate to via the iPhone Safari mobile browser. A Web-based application such as this is called a Web app.
iPhone Web apps.
Web apps are accessed by visiting a Web address on the iPhone, the same way a user visits any Web site on the device. What makes Web apps unique, however, is that they are essentially iPhone-specific Web sites that are designed exclusively for viewing on the iPhone. iPhone Web apps can exist as games, blogs, learning tools, and much more—all designed with the beautifully unique Apple Human Interface Guidelines for iPhone Web development in mind.