Hi Drew,
> I am creating a public facing application to be used for an event and an internal use Dashboard. I would like to know if there is a way to show the current number of users on the public application as an indicator box in a dashboard.
I suppose this might be possible if the information on "the current number of users on the public application" was stored in a hosted feature layer. This might be possible by using some custom python scripts that would query for the current number of users accessing your web app - although I am not a developer.
You could start to learn about the REST API here,
Working with users, groups, and items—ArcGIS REST API: Users, groups, and content | ArcGIS for Devel...
Hope this helps,
