The Category Gallery configurable app template allows you to create a gallery of content from a group. Users of the app can filter and search content in a variety of ways, including using group content categories. You can also configure the app to include a custom header that you define via HTML.
The Category Gallery template is new at 10.7.1.
To see the options available for this template, search your ArcGIS Enterprise portal using the app template name and open the app template item's detail page.
The Category Gallery app template requires a group. To allow app users to search on content categories, the group you use in the app must have categories configured.