YouTube Thumbnail Grabber - Paste in a YouTube video url, get the thumbnail in all sizes.
GenYTB - Search and Download YouTube videos
Get YouTube Thumbnail - Easy way to get the thumbnail image from a YouTube video
YoutubeMultiDownloader - Just like its name YouTube Multi Downloader, it is an online website for downloading the videos of downloading without using any video download and accelerator.
Download YouTube Thumbnail - Download YouTube Video Thumbnail Image - Support most websites
2conv.ch - 2conv.ch is expert in downloading online videos to MP3/MP4 files from 1000+ websites, including YouTube, Facebook, Twitter, Dailymotion and more.