If you like using the latest apps first or just forgot to download the latest app and try it then you have good news, now Apple has started taking pre-orders for coming soon apps.Earlier even Google had enabled the feature to notify the user when available for download.
App developers can set the app for pre-orders 90 days before the launch date of the app so that users can directly pre-order the app within this time frame.
Once user hit on pre-order, then the app will be automatically downloaded on your devices once released and will be charged for paid apps and if any prices fluctuation before pre-order or after publishing the app then the user will be charged the present or the lowest price.The feature is now available on iOS, Apple TV, and macOS.