ChemDraw: How can I reinstall ChemDraw for iPad if it’s no longer available in the App Store

How can I reinstall ChemDraw for iPad if it’s no longer available in the App Store?

ChemDraw for iPad has been discontinued and it’s no longer available in the App Store. If you remove the software from your device you will not be able to re-download it. Apps are removed from the App Store all the time and Apple claims on their terms and conditions that content may not be available for re-download if that Content is no longer offered on their services (https://www.apple.com/legal/internet-services/itunes/us/terms.html).