Windows Phone QUICK HELP - Fast App Switching

I have a Windows Phone C# app that is a children's interactive book. I need Fast App Switching support added to the app so that: Code needs to be added to make sure that the following scenarios are handled: 1. Rapidly leaving and returning to the application does not cause the application to crash and application state is retained. The app should pull up the page where the user left off. 2. Tombstoning - Application is able to resume successfully from tombstoned state. The right behavior is to resume the app to the same page and keep UI in the state as before tombstoning. Such as text entered by user before tombstoning is remembered, check boxes checked status is remembered, etc). 3. Fast app switching - Pressing start,then re- launching the application restores the application to its initial state.