Downie - Video download for OS X. Downie supports at this moment over 1,000 different sites.
4k Video Downloader - 4K Video Downloader is a software program that helps people download video files from sites such as Facebook, YouTube and Dailymotion.
Save IGTV - IGTV Downloader - Save IGTV Videos on any device with the fastest IGtv video downloader.
Video DownloadHelper - Browser extension to download videos from the Web
Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.