title: In App Purchase with restore transaction
body: <p>Can anyone please explain me how restore transaction works with Auto-Renewable Subscriptions.</p>
  
  <p>I have read apple <a href="http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/StoreKitGuide/RenewableSubscriptions/RenewableSubscriptions.html#//apple_ref/doc/uid/TP40008267-CH4-SW5" rel="nofollow">http://developer.apple.com/library/ios/#documentation/NetworkingInternet/Conceptual/StoreKitGuide/RenewableSubscriptions/RenewableSubscriptions.html#//apple_ref/doc/uid/TP40008267-CH4-SW5</a>
  But did not get this.</p>
  
  <p>I have an application which does not have Login authentication. If user purchase the Product from one device and same user install the app on another device how can i know that the user who installed the app has already purchase the product.</p>
  
  <p>if user goes to purchase the product they already purchase is there any delegate methods for it that we can know that is user has already purchase the product.</p>
  
  <p>Thanks.</p>