switch (transaction.transactionState) {

        case SKPaymentTransactionStatePurchasing:

            // show wait view here
            statusLabel.text = @"Processing...";
            break;

        case SKPaymentTransactionStatePurchased:

            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];

            // remove wait view and unlock iClooud Syncing
            statusLabel.text = @"Done!";

            NSError *error = nil;
            [SFHFKeychainUtils storeUsername:@"IAPNoob01" andPassword:@"whatever" forServiceName: kStoredData updateExisting:YES error:&error];

            // apply purchase action  - hide lock overlay and
            [oStockLock setBackgroundImage:nil forState:UIControlStateNormal];

            // do other thing to enable the features

            break;

        case SKPaymentTransactionStateRestored:

            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];

            // remove wait view here
            statusLabel.text = @"";
            break;

        case SKPaymentTransactionStateFailed:

            if (transaction.error.code != SKErrorPaymentCancelled) {
                NSLog(@"Error payment cancelled");
            }
            [[SKPaymentQueue defaultQueue] finishTransaction:transaction];
            // remove wait view here
            statusLabel.text = @"Purchase Error!";
            break;

        default:
            break;
    }