title: How to Design UIViewController Visual Layout Flows like iOS Developer Library
body: <p>Which is the tool used to design UI View Controllers and storyboard for iOS NIB UI?</p>
  
  <p>[UPDATE]
  I'm looking for a UI Design Tool in terms of layout sketches more than the StoryBoard design of XCode. The aim is to design the flows of the UIViewControllers as depicted by Apple in the iOS Developer Library.</p>
  
  <p>I have checked some layout UML Class diagrams tools like Visual Paradigm, Magic Draw, etc, but they do not have a visual layout for the UI as well.</p>
  
  <p><img src="https://i.stack.imgur.com/9kWre.png" alt="iOS Developer Library UI Flow Example"></p>
  
  <p><img src="https://i.stack.imgur.com/glH9U.png" alt="High-level flow interface Example"></p>