title: Running first singleview ios application on Xcode
body: <p>I'm writing a very first program for iOS in Xcode 6 (Single-view application). 
  I added a label and ran a simulation. </p>
  
  <p>I have seen this label on a simulator. But when i added an additional button on a Main.storyboard's ViewControler and rebuilt the project - the was no any button. It seems like simulator ran first version without the button. How can i launch last version of my project on a simulator?</p>
  
  <p>Thanks.</p>