Welcome to Android Central! Moved from the Android Apps forum to the Android Wear forum, since the former is intended for developers to promote their apps.
My favorite watchface app is
WatchMaster (not to be confused with WatchMaker). Some really nice watchfaces that look like real watches (which I think would be most appropriate for a TAG). The free app has some good faces, but I paid full price to get access to all faces. I currently have 50 saved, and rotate them regularly.