Hi Repitaph.
Thank you for your message.
Since Cubasis does not have a demo mode, I assume you’ve been mentioning Cubasis LE here, correct?
Cubasis LE can be unlocked from demo mode, via connecting a compatible device (see the list of supported devices on our Cubasis LE website).
In-App Purchases can be restored via tapping the Restore Purchases button located in the In-App Store of the app.
Please let me know if this helps to solve the problems.
Thanks,
Lars