R – Detecting with code if your iPhone app is live vs test

Thomas, you should definitely read Apple's FAQ on In-App Purchase: https://developer.apple.com/library/content/technotes/tn2413/_index.html#//apple_ref/doc/uid/DTS40016228-CH1-RECEIPTURL

Always verify your receipt first with the production URL; proceed to verify with the sandbox URL if you receive a 21007 status code. Following this approach ensures that you do not have to switch between URLs while your application is being tested or reviewed in the sandbox or is live in the App Store.

So yes, they are kinda crazy. But we knew that, didn't we?

When you verify the receipt, if you receive a status code 21007 it means its a sandbox receipt. Look here: https://developer.apple.com/library/content/technotes/tn2413/_index.html#//apple_ref/doc/uid/DTS40016228-CH1-RECEIPTURL

What url should I use to verify my receipt?
Always verify your receipt first with the production URL; proceed to verify with the sandbox URL if you receive a 21007 status code. Following this approach ensures that you do not have to switch between URLs while your application is being tested or reviewed in the sandbox or is live in the App Store.

The 21007 status code indicates that this receipt is a sandbox receipt, but it was sent to the production service for verification. A status of 0 indicates that the receipt was properly verified. See WWDC 2012: Managing Subscriptions with In-App Purchase for more information.