title: How do I add a TabBarItem to a UITabBarController that creates a view over any other view that is currently shown in the TabBarController?
body: <p>so in my App i have a UITabBarController with 4 tabs/views (1 - 2 - 3 - 4).
  Basically, what i want to do is add a 5th TableBarItem in between those 4 existing 
  TabBarItems(1 - 2 - HERE - 3 - 4).
  The problem is, I would like my new TabBarItem to be more like a UIButton.
  This means, if you klick it, it should bring up a transparent UIView or UIViewController over the UIViewController of the tab/item that is currently selected (1,2,3 or 4).</p>
  
  <p><em>For Example, if you selected tab/view 3 and then press the new item, it should slide in a half-transparent view over tab/view 3.</em></p>
  
  <p><em>Another great example for this is the Tumblr app.</em></p>
  
  <p>My question is, how do i create a TableBarItem that doesn't refer to a ViewController, but creates a view over the ViewController that is currently on screen? </p>