title: iOS: How to store username/password within an app?
body: <p>I have a login-screen in my iOS app.
  The username and password will be saved in the <code>NSUserDefaults</code> and be loaded into the login-screen again when you enter the app again (of course, <code>NSUserDefaults</code> are permanent).</p>
  
  <p>Now, the user have the possibility to disable the username/password saving feature.</p>
  
  <p>So the <code>NSUserDefaults</code> will be cleared then.</p>
  
  <p>But In my app I need this username/password for database queries for the user.
  So: Where to store the data except <code>NSUserDefaults</code>? 
  (This place can / should be deleted when the user quit the app or logout).</p>