In-App Purchases is often chosen as a main monetization channel for many applications, because of many advantages of the freemium model.
However, correct IAP implementation is notoriously difficult, and Apple are particularly strict in their approval policies for apps that contain IAP.
When you plan on selling anything via your app, you need to determine how does it map to the Apple’s vision of the IAM world:
Products that are used one time, after which they become depleted and need to be purchased again, are usually implemented as consumables. For example, fish food in a fishing app could …