The Benefits of Testing In-App Purchases Without a Sandbox: A Guide for Developers.

Optimizing Storage for In-App Purchases: A Comparison of Plists, NSUserDefaults, and SQLite Databases

Mastering Sandbox Test Accounts for iOS In-App Purchases: A Comprehensive Guide to Avoiding Account Disablement

Implementing Monthly Subscriptions in In-App Purchases for iPhone Apps: A Comprehensive Guide