MapViewer BETA supports the long-awaited Group Layer function, so you are able to hierarchically display multiple layers with relatively easy switching on and off.
You can use MapViewer BETA as a webmap in a WebApplication like the classic webmap. However, Group Layers are not supported and the layers are displayed as the classic webmap. Right now, you can not use Map Viewer BETA like a WebApplication, because a lot of features are missing, and you can't use WebApplication as you miss (Group Layers) functionality from the Map Viewer BETA.
I ask for Group Layer function (and other relevant functions) to be available in the WebApplication (or alternatively all/more functions from WebApplications to be included in MapViewer BETA)