在运行时检测哪个国家/地区的App Store是从我的iPhone应用程序下载的？

I have a feature in my iPhone application that, for business reasons, should only be shown/available to customers in the US. If I want to release this app to App Stores outside the US, what's the best way to figure out which country I'm in without relying on user-defined settings such as language and locale?I have a feature in my iPhone application that,