title: Ios how to get a list of already purchased products?
body: <p>I'm building an app that uses In app purchase. I'm using non-consumable product types.</p>
  
  <p>Everything works ok (setting up products, buying...).</p>
  
  <p>What I would like to do is to verify which products a user had already purchased (when reinstalling app or changing device)?</p>
  
  <p>Is that possible?</p>
  
  <p>Thanks</p>