I'm looking for the latest advice on detecting customers who have bought my app prior to its conversion to freemium, so I can offer them a free period. This seems like a pretty common thing to want to do.
I'm adding a range of subscriptions to a previously "paid" app, and don't want to annoy customers who have recently bought it outright. Over the last decade there has been a great deal of confusing advice posted on this subject, so does anyone know the best way to tackle this when supporting Sonoma and later? I'm currently implementing the new subscription solution based around SubscriptionStoreView.
I don't have a server to support my app as it isn't cost-effective for my situation, and much of the Apple video content seems centred around having one. Is it possible to do the receipt checking and detection of original paid purchase date in-app? Maybe using StoreKit2?
Can I do this with introductory offers?
Any help greatly appreciated.
UPDATE: I've just started re-watching the WWDC 2022 Video "What's new with in-app purchase" and it seems that AppTransaction is the way to go. Any thoughts on this?
To learn when a customer first purchased your app and determine the app features they’re entitled to, see Supporting business model changes by using the app transaction.