Great Downloader easy to use can convert into multiple file formats. Fast and impressive
MetaX for Windows - MetaX for Windows, port of https://alternativeto.
Video DownloadHelper - Browser extension to download videos from the Web
veotag - veotag lets you display clickable text, called "veotags," within an audio or video file.
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
iFlicks - iFlicks is the best and most complete video and metadata handling solution available for macOS.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.