App Store now offers pre-order
December 12th 2017
Apple:
Now you can make your new apps available for pre-order on all Apple platforms. Customers can see your product page and order your app before it's released for download. Once your app is released, customers will be notified and your app will automatically download to their device. For paid apps, customers will be charged before download.
The pre-orders can be set up to 90-days into the future and at least two out.
Nice feature that may help with launch timing or just trying to build awareness of an upcoming app.