I have integrated In App Purchase (Auto-Renewable subscription) in iOS & Android. Both are working fine. I have certain doubts about validating the IAP using cross platforms like:
How multiple user when login in one app, how does the subscription for one particular works? (For Example, if user A has standard plan & after logout from the app. If user B logins in the same plan who has premium plan. How the iTunes will manages plan of IAP for particular user?)
Also what if user's who has android device when switch to iOS, then how to validate the IAP from android to iOS or vice-versa? (Like Netflix)
What if user A who has purchased standard plan on android and now switch to iOS & upgraded to platinum plan. So at the end of the standard subscription plan , will the standard plan be stopped & platinum will continue.. or standard plan will be counted too??
Any help will be appreciated. Thanks
Like @Paulw11 said, you'll need to manage subscriptions on your own server. Any receipt validation will only validate against that users App Store or Play Store account on the device, not the logged in user of your app. Obviously, Apple can't validate a Google purchase or vis-versa.
To answer your questions directly:
There is a tool, RevenueCat, that might be worth checking out. It's essentially a subscription backend-as-a-service that handles exactly what your trying to do.