Any (early) experiences with auto-renewable subscriptions for iOS

Question

Apple finally introduced the so called auto-renewable subscriptions yesterday. Since I only have few (sandbox-only) experiences with in-app-purchase, I\'m not sure that I go

Answer 1

To determine whether a user has a valid subscription you either have to a) validate the existing receipt as described in the doc you linked to, or b) have the user repurchase the subscription and get a response back from Apple.

The latter doesn't need any server-side interaction on your end, but is wrong and liable to get you rejected, because you'll need to prompt the user to effectively 'repurchase' your product every time you want to verify their sub.

So, the only option is - as Apple recommend - to store and then verify the store receipt.

Now, I suppose in theory you could save the store receipt on device, and verify it that way. However, I think you'd have to be crazy to do this, because the new verification system requires a shared secret which you'd have to bundle with the app itself (a really bad idea).

Which means the answer to your question "can I work with an iOS client only" is 'technically yes', but to do so would be highly ill advised due to a number of security issues. Fortunately, the server side architecture you need to build is very simple - just linking iTunes receipts with UDIDs of devices, and a simple API to communicate with them. If you're not able to work that out, I'm sure very soon existing third-party in app purchase helpers such as Urban Airship will add auto-renew subs to their products.

Linking UDID and receipt works fine because when the user makes a purchase on another device, Apple automatically restores their previous purchases. So you can save the receipt again, this time tied to a new UDID.