title: iOS push services: is an invisible push notification possible?
body: <p>I'm building a iPhone application which depends data from an online database. </p>
  
  <p>To update the data in the app i could check at a certain time interval if an update is necessary but it is way cooler if i could use a push services which sends a notification to the app letting it know it is time for an update. </p>
  
  <p>i'm not talking visible push notifications here, just a invisible push notification to fire the update method in my app. </p>
  
  <p>Is there a standard way to do this or could i use apple's push notification services for this purpose ?</p>
  
  <p><strong>With other words: i'm now using pull to get updates, is there a push way to let the backend of my app know it is time for an update?</strong></p>
  
  <p>Edit: And if it is impossible, what would be good time interval for the update (0.03 kb if there are no updates). Is it to much to check it every 30 seconds ?</p>