Is there one subscription for multiple products?
No. Not every customer needs all versions of our software, therefore we have decided not to combine different product versions to one subscription.
Merlin Project, Merlin Project Express and Merlin Project Go are individual products for different operating systems (macOS and iOS) and scopes. They require individual subscriptions.
If you have questions regarding subscriptions in the App Store, you will find some answers on the Apple help page.