Installing Purchased App On New Device? [PlayStore ISSUE]
I was able to solve the issue by doing the following.


Install the ACR Licence apk (which I got from my backup, or you could find the file online)
Open the Play Store page for the app (the button should be showing Uninstall)
Uninstall the application (from within Play Store)
Done


Now you should be presented with the Install button. Installation should work as normal (no re-purchase required).