In order to check the tags on an app in real time, it is necessary to use a proxy to intercept the hits as they are sent.
We use one of two programs we have found to work well for such purposes
It requires a little setup.
Here is an example of said setup when using Fiddler with iOS: https://docs.telerik.com/fiddler/Configure-Fiddler/Tasks/ConfigureForiOS
We also recommend the use of our auditing tool Stream Inspector.