title: UIWindows or UIViews
body: <p>I need three different sections in my app: a login screen, a main screen, and one that takes place in landscape mode, all totally different. I saw Apple insists that an app should have one window, so I'm asking: what would be best to use for this? Three big windows, or views?
  And how should the hierarchy look like? I don't have experience with layers for example. And while the login panel can go away after the user gets logged in, the other two must remain the same no matter which one of them is visible.</p>
  
  <p>Also, no matter what your answer is, how exactly would the new UIWindow flow look like? How do I attach it instead of the initial one? do they have layers? etc.</p>
  
  <p>Thanks!</p>