TubeIcon Web, a web-based version of TubeIcon, just launched today. TubeIcon Web is simple and easy, designed for users who don't need all the features of the desktop TubeIcon but still want to create nice video icons. TubeIcon Web allows you to upload a background image for your icon, then add an episode number, series title, and channel name to your icon. It works on all operating systems.
The web version of TubeIcon does not currently support uploading a video to grab a frame from, however, you can grab an icon background from a video on YouTube. If you need to save configuration options, use a wider range of styles, or grab a frame from a video without uploading it to YouTube, you should use the desktop version of TubeIcon.