3.1.5(a) Goods and Services Outside of the App: If your app enables people to purchase goods or services that will be consumed outside of the app, you must use purchase methods other than in-app purchase to collect those payments, such as Apple Pay or traditional credit card entry.
So if I have two apps A and B, and app A only allows you to buy a license to unlock content/features in app B... no commission is due since what I buy in app A is consumed in app B, i.e. outside app A? :D
So if I have two apps A and B, and app A only allows you to buy a license to unlock content/features in app B... no commission is due since what I buy in app A is consumed in app B, i.e. outside app A? :D