title: How do I implement a persistent/universal right bar button item like Music app and Pandora's "Now Playing" buttons?
body: <p>I am writing a streaming music app and I really like the universal "Now Playing" buttons in Music app and Pandora. I am trying to implement them myself. Unfortunately, the methods I tried led to me confusing myself as well as people who tried to help me. Here's what I've tried so far, all of which don't work/work partially:</p>
  
  <ul>
  <li>Using a <code>static UIBarButtonItem</code> in all controllers (works inconsistently, sometimes no segue)</li>
  <li>Adding a button manually to all controllers in Interface Builder (works, but results in a fade-out/fade-in animation when transitioning)</li>
  <li>Creating a view controller which had a <code>static UIBarButtonItem</code> from which all controllers subclassed (eliminated the no segue issue from method 1, but still behaves inconsistently)</li>
  </ul>
  
  <p>TL;DR: I don't know how to implement a universal right bar button item. Please tell me how.</p>
  
  <p><a href="http://cl.ly/1S3N0m3G3k3c" rel="nofollow noreferrer">Demo Project</a> with a blank representation of my hierarchy.</p>
  
  <p>EDIT: Pandora's developer Neil Mix <a href="https://stackoverflow.com/a/855879/1593651">answered this question</a>. Exactly the same issue. But I did not understand it. It would be great if someone could explain his method.</p>