The add-on is meant as an add-on, not an app. It is not meant to have a UI.
It's pretty powerful to display all your data into common formats. You can then create dashboards with those standard fields without having to re-invent the wheel every time.
The CIM provides normalization for many types of events and provides the data models for the Common Information Models.
In addition you can find other ones in the splunk apps.
Other than those resources, you have to create your own.
To build on aelliott's comments above, while this is not an app with a UI, we ship with approx 15 datamodels out of the box that can be used with the search app's Pivot interface. These can also be accelerated to provide a high performance column store that can be queried with "| tstats".