I exchanged with my Microsoft rep about having a demo app in addition to the regular app. Here is his reply :
I have been working to get an answer on this from the Store team approvers for about a week. The approvers have asked that for application which have been converted using the “Desktop Application Converter” (DAC) implement the free trial within the application. They have decided not to allow two application version.
This link should show you how to set this up.
I studied carefully the link above, but I am afraid it is going over my head. I know fairly well how to implement WinAPI declares, but this is mainly C# and I do not see clearly what is asked of us.
It would be great if Christian could create a plugin from that, akin to what he has done for the MAS.