title: Auto-update of an Android app never happens
body: <p>I have a somewhat unusual Android app in the Play Store that's running on dedicated devices 24/7 (it collects sensor data, it's not meant to run on phones used for anything else). I would like the app to auto-update without user interaction, but that never seems to happen. Why could this be?</p>
  
  <p>Some more background:</p>
  
  <ul>
  <li>Auto-update is explicitly turned on for the app on the devices.</li>
  <li>Other apps do seem to auto-update.</li>
  <li>The app stops and restarts itself every 12 hours; mostly to whack the app out of any weird state it might get into and clear memory, but I was also hoping this would give it a chance to auto-update. There is a 10 second delay until the app restarts.</li>
  <li>The devices are mostly old phones (HTC Desire C) running Android 4.0.4</li>
  </ul>
  
  <p>This is fairly hard and time-consuming to test so any experiences shared with similar requirements could be helpful.</p>