What exactly do you want them to be able to see in the web app?
Edit: Looking at what you wrote again, I'm thinking what you're looking for is for the user to be able to see the "Casper Admin" item under the Settings tab. Is that right? Because that's the closest thing to a Casper Admin Framework I know of.
If so, unfortunately, the only way to do this is to give them access to "Use Casper Admin" under the Casper Admin privileges, BUT you also need to give them Save privileges there as well. Without it they won't see it at all. That means they can change your configs, categories, and other stuff. There is no Read only access to Casper Admin in the JSS available right now. The physical app can be controlled, but not the web view.
They'd also need to be able to View the Settings tab further up the list.