iOS In-App Purchase - if user of iOS app already have paid subscription?

Question

I plan develop mobile app with pro version and paid subscription business model. I have iOS and Android apps. Here is very important question, if user already has paid subscription in Android app and then log in into iOS app.. Can I implement my own business logic in iOS app to give access to pro version of app? Whether Apple will reject my app in such case?

For Android in its docs I have found this:

If you sell subscriptions on a web site, for example, you can add your own business logic to your Android app to determine whether the user has already purchased a subscription elsewhere, then allow access to your content if so or offer a subscription purchase from Google Play if not. You can implement your own solution for sharing subscriptions across as many different apps or products as you want. For example, you could sell a subscription that gives a subscriber access to an entire collection of apps, games, or other content for a monthly or annual fee. To implement this solution, you could add your own business logic to your app to determine whether the user has already purchased a given subscription and if so, allow access to your content.

I tried to find something similar in Apple's In-App Purchas documentation but didn't find.

Can someone faced with such problem, you can tell whether to do so, and if not, how best to proceed in this case?

Thanks!

Answer 1

You can obviously do this. As many of the subscription based apps are already doing this. You just need to keep a common DB across all platforms for your users.

So if a user makes a purchase on android platform, you can record it in your DB. And when he will login on another platform, you can check your DB whether this user has already made a payment or not and accordingly handle that.