Daren,
I think you don't understand the difference between installing PRO features and creating/adding a new page or App.
Let me explain, App's it's a PRO functionality, after installing Gridbox, to start using them you need to install them.
How to install App you can see here:
The app you need to install only once, during the license period. After App installation, you can add/create the unlimited number of Apps even without an active subscription.
How to add/create a new App you can see here:
The same with all Gridbox PRO functionality,
PRO functionality should be installed during the license period after that it could be used without a time limitation