Read original post by Matteo Pagani at Qmatteoq.com
When I started to play with Windows Store apps development for Windows 8, one of the things I liked most was the base LayoutAwarePage class, from which every page inherits from. This class introduces a built in support for managing the different visual states of the page using the VisualStateManager: every time the page state changes (Portrait, Landscape, Snapped or Filled), a specific state is triggered so, as a developer, it’s really easy to apply animation and changes the layout of the page.
Unfortunately, this built in helper is missing in Windows Phone, so you have to manually manage the orientation from portrait to landscape or vice versa: Windows Phone is able to, automatically, arrange the controls when the orientation is changed, but often isn’t enough because you want to deeply change the layout of the page according to the orientation.