XLInAppPurchase
  
  Created by Richard Wei on 11-11-21.
  Copyright (c) 2011 Xinranmsn Labs. All rights reserved.
  
It's an encapsulation of  In-App Purchase (StoreKit) APIs.

To use this in your project, just build this and add XLInAppPurchase.framework to your project.

There's 2 ways to implement XLInAppPurchase manager:
1. Initialize XLInAppPurchaseManager with -initWithProductIdentifier:delegate:loadStore:enableNotifications:. Start purchase by calling -makePurchase;
2. Initialize XLInAppPurchaseManager with -initWithProductIdentifier:. Then call -loadStore to load store. Start purchase by calling -makePurchase;