title: Can the iPhone detect height position?
body: <p>I have an idea for an iPhone game / app that needs to be able to track height position of the iPhone. I am new to iPhone development so I don't know how the accelerometer works. But the idea is that the user should place the iphone on a flat surface (with the iPhone back against the surface). The user will the lower and raise the surface periodically and the iPhone should be able to track this movement. We can assume that the surface will go back to its original position so we only care about how much it was lowered / raised from its original position during the movement.</p>
  
  <p>The amount raised / lowered will be a few centimeters. Is this possible to track and how would you go about solving this? </p>
  
  <p>Thank you very much for your help!
  Best regards,
  Lukas</p>