Beginning in iOS 11, users will be able to browse in-app purchases directly from the App Store. Users will even be able to make a purchase before the app is finished downloading.
During the iOS 11 beta period, the promoted in-app purchases are being displayed within the App Store, but the option to buy is not enabled.
Starting this fall, when iOS 11 is released, users will be able to make in-app purchase transaction from the App Store. This means that developers will have to update their apps to support this feature.
Once the GM version of Xcode 9 is released, developers will simply have to implement a new delegate method inside of SKPaymentTransactionObserver. This method will allow the in-app purchase transaction to occur from within the App Store.
Developers will also have the ability to control which in-app purchases are promoted for each specific device type. If you are a developer, you can learn more about the new requirement for promoted in-app purchases from this link.
[via Apple Developer]