Read original post by Colin Eberhardt at ScottLogic
About a month ago I published an article which demonstrated how to create a WP7 application using static HTML pages and PhoneGap. Whilst PhoneGap makes the packaging of HTML / JavaScript / CSS and images into a breeze, one thing it doesn’t do is provide correct back-button support. Correct back-button support is a mandatory requirement for marketplace certification. Hitting the back button should navigate back through the various screens of an application. Hitting the back-button on the first screen should terminate the application.