I would love if Jamf could keep track of that. As it is, we are using Classlink, which sort of keeps track. It is like having an iPad within an iPad (what the iPad should be). You setup apps and websites within Classlink. Classlink knows your login name/password for all apps (why can't Jamf do that?). Everytime you click on an app within Classlink, it records it.
Obviously, it does not record links clicked outside of Classlink, but it gets close to what you want.
I know this post is old but....Checked with Jamf support on this a couple days ago. They are still not able to report on iPad device/app usage.
I did find something kind of useful though for anyone interested. Was messing around with connecting my instance of Jamf Pro to Power bi to see if I could develop some meaningful reports. Found a field that you can select called "mobileDeviceDetails.percentage_used"
Seems pretty vague but at least its something. Anyone else still working on this type of thing? Any suggestions or improvements since 2018 you've found?