Fawesome TV is an app published with Android TV support recently that acts as a large curation of media from a variety of different genres. It was created an uploaded by Future Today Inc, which links to a recipe website.
Not all of their apps seem to be regularly supported. For example, the TechSmart for Google TV app was last updated in September of 2014, but the app still does seem to work with a DPAD.
Fawesome TV in particular appears to have a wide collection of media and a lot of content to consume. Although it’s not using the Leanback UI, it still works pretty well. The app is free to download on the Google Play Store.