Mobile WMS uses an application.cfg file to setup the behaviour on the mobile device. When you need to make configural changes to the app, you need to know more about what are the built-in possibilities. Now it is possible for you to actually make the changes from the AX/D365FO client.
From the client you can find the page creator by navigating to: Mobile WMS/Setup/Customizations/Page Creator
Offline
Page creator does not support offline specific functionalities.