YouTube Kids launched in 2015, as a portal for child-appropriate content with parental controls. It has been over two years since then, but for most of that time, only apps for Android and iOS were available. An app for select smart TVs was released in April, and now Android TV owners can use the service as well.
Judging from the screenshots, this appears to be the same exact app released for smart TVs.
Android TV app for YouTube Kids now available was written by the awesome team at Android Police.