I guess this would involve changes to MoodleWeb as well, but...
It would be great if resources could have an option to be hidden from or visible to just the App.
For example you might have a Label with images and formatting etc. which looks great via a browser, but fails to render correctly in the App. If you could hide such a Label and instead show one designed for the App that would be . Another example might be an activity that currently sends you to the website in a mobile browser (eg Workshops) and so is currently not a great fit for the App.
More background Info...
I'm thinking specifically of a Bootstrap responsive grid that I'm working on which is inserted as a Label on the Front Page. It works well on screen sizes down to xs, but smaller than that I just want it hidden with a different grid visible specifically for xs screens. With Bootstrap this is achievable in a browser. But the App still tries to render everything which does not work out well as plenty of bootstrap components eg. modals, popovers, cards (understandably) don't work in the App. This is on 3.4.