title: iOS app update size is much bigger than app size
body: <p>We have a problem that our app update regularly shows up way bigger than the app actually is (with app thinning).</p>
  
  <ul>
  <li>App update size: 142MB</li>
  <li>App size on app store: 89.1MB</li>
  <li>App size on device: 84.3MB</li>
  </ul>
  
  <p>See the attached screenshots:</p>
  
  <p>What can be causing this?</p>
  
  <p>Screenshots were taken on an iOS 9 device. But the same can be observed on iOS 8.</p>
  
  <p>I see difference for other apps as well but usually just a few MB at max.</p>
  
  <p>App size:</p>
  
  <p><a href="https://i.stack.imgur.com/bnDTF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bnDTF.png" alt="enter image description here"></a></p>
  
  <p>Update Size:</p>
  
  <p><a href="https://i.stack.imgur.com/wVBtN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wVBtN.png" alt="enter image description here"></a></p>