Open the add-in's Settings window and define uniform colours or colour schemes for the spatial element types.

Set the highlight's and masses' transparency level.

Open the 3D Rooms dock panel.

Open a 3D View and select the Rooms, Zones, etc. that you want to highlight.

Use the context menu to generate, select or delete Masses in place of the spatial elements.

Use the view transparency settings to improve visibility of the highlighted element. 

If you generate Masses, make sure that the Mass type is visible in the view.

The installer that ran when you downloaded this app/plug-in from Autodesk App Store will start installing the app/plug-in. OR, simply double-click the downloaded installer to install the app/plugin. You may need to restart the Autodesk product to activate the app/plug-in. To uninstall this plug-in, exit the Autodesk product if you are currently running it, simply rerun the installer, and select the "Uninstall" button. OR, click Control Panel > Programs > Programs and Features (Windows 7/8.1/10/11) and uninstall as you would any other application from your system.

• The Zoom command switches to a floor plan if there's an open one.
  If there's no open floor plan, it zooms to the selected elements in the 3D view. This is a known Autodesk® Revit® API issue.
• The selection is not visible in the model if a dock panel is active.
  The user must activate the view (eg. by clicking in the view with the middle button) to make the selection visible. This is a known Revit API issue.
• MepSystemZones don't have geometry in some cases, as the document's active view is null.