title: iOS detect movement of user
body: <p>I want to create a simple app that draws a simple line on screen when I move my phone on the Y-axis from a start point to end point, for example from point a(0,0) to point b(0, 10) please help</p>
  
  <p>demo : </p>
  
  <p><img src="https://i.stack.imgur.com/wtPo3.png" alt="enter image description here"></p>