No restore button for in app purchase causes rejection

Question

I am implementing an application using in app purchase with non-consumables items, it was rejected by apple and the reason is:

We found that your app off

Answer 1

Use the following to restore the products ID's that user did purchased from your app

- (void) checkPurchasedItems
{
   [[SKPaymentQueue defaultQueue] restoreCompletedTransactions];
}// Call This Function

//Then this delegate Function Will be fired
- (void) paymentQueueRestoreCompletedTransactionsFinished:(SKPaymentQueue *)queue
{
  purchasedItemIDs = [[NSMutableArray alloc] init];

  NSLog(@"received restored transactions: %i", queue.transactions.count);
  for (SKPaymentTransaction *transaction in queue.transactions)
  {
      NSString *productID = transaction.payment.productIdentifier;
      [purchasedItemIDs addObject:productID];
  }

}

the purchasedItemIDs will contain all the product IDs that the user purchased it .. you could put a button to call this function when it finished you show all these products to enable the user to download it again.