YouTube Thumbnail Viewer, Grabber, Downloader!

Youtube is a free online service to see and get thumbnail from youtube videos. just copy yotube url, paste in the box, then see the result, The next is grab and download a YouTube video's thumbnails at various sizes including default image, hqdefault.jpg, mqdefault.jpg, sddefault.jpg, and maxresdefault.jpg(HD Resolution 720p)