| I don't think the section you quote tells the whole story > If you want to unlock features or functionality within your app, (by way of example: subscriptions, in-game currencies, game levels, access to premium content, or unlocking a full version), you must use in-app purchase. > Apps may use in-app purchase currencies to enable customers to “tip” the developer or digital content providers in the app. Using "must" for unlocking features and "may" for tipping is pretty odd if they need to be treated identically. This is especially clear if you look later in the document where an almost identical phrasing is used in the other direction: > If your app enables the purchase of real-time person-to-person services between two individuals you may use purchase methods other than in-app purchase to collect those payments. > If your app enables people to purchase physical 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 Certainly the person-to-person transactions aren't required to use purchase methods other than in-app purchase despite the use of "may" in the same context. This section could probably invalidate it although its extremely confusing because only "reader" apps (3.1.3(a)) are allowed to direct to other purchasing methods but physical goods apps are required not to use IAP. How would they avoid using IAP if they can't direct to other mechanisms? > Apps and their metadata may not include buttons, external links, or other calls to action that direct customers to purchasing mechanisms other than in-app purchase, except as set forth in 3.1.3(a). |
> (vii) Apps may enable individual users to give a monetary gift to another individual without using in-app purchase, provided that (a) the gift is a completely optional choice by the giver, and (b) 100% of the funds go to the receiver of the gift. However, a gift that is connected to or associated at any point in time with receiving digital content or services must use in-app purchase.