I'm deciding between offering an up-front purchase or a free app with a (one time) IAP-unlock and a free trial.
However in this app there is no good way to reduce functionality. So after the trial period (or without "buying" the free trial) the app would be kind of useless.
Is that ok?
I searched for a while now but couldn't find definitive answers.
I read about 4.2 Minimum Functionality and get that point if it applies to the whole app.
But what if the IAP-unlocked app is not minimal but the app would be once the trial expires and the users doesn't buy the IAP?
Thanks.
BTW, I'm a bit uncertain about what official agreements exist.
I see the Apple Developer Agreement and the Apple Developer Program License Agreement. Then the App Store Review Guidelines.
Are there other agreements?
Tthere is no problem with this. This is a classic "free trial".
However, you should think of the marketing aspects. If the user can't do anything at all without the subscription, many will dump it after the free trial. If you can offer some free functionality, that will keep them using it and keep them seeing your subscription opportunity. Think of the free functionality as a built-in advertisement.