Just built this Simple YouTube downloader for video, audio & subtitles. It also comes with a built-in YouTube search (originally created by Tim Ivey at codepen.io). Enjoy: http://yt2u.com

A couple of screenshots:

Download Example

Search Result Example

Search Result script is copyright (c) 2017 by Tim Ivey (http://codepen.io/timivey/pen/jEXxZY), I've only amended it a little to serve my purposes.