App Store: developers can offer pre-order apps and discounted prices for subscriptions
The first novelty allows developers to offer a pre-order system for their applications, both on the App Store on iOS and the Mac App Store on Mac or the App Store on tvOS. The pre-order works just like an album or movie on iTunes: the download of the app will automatically start when the app is available for download on the App Store. If we click today on the button "Get" for the INSIDE game for example, it will download itself on the iPhone or iPad on December 15, a date defined by the developer. It should be noted that users will be notified of the download before it is done.
The second ad is for subscriptions with the help of in-app purchases. Apple now offers the opportunity for developers to offer a reduced rate (or a trial period) for a period of time before switching to the normal rate. For example, we can think of a newspaper that offers free the first three months of subscriptions before moving to € 5 / month, and this automatically. It is now possible, provided users are on iOS 11.2 at least. If you are a developer, Apple's documentation is available