Great Downloader easy to use can convert into multiple file formats. Fast and impressive
Minimize play in background - This all-in-one application for android allows you to watch all videos while using a smartphone.
Video DownloadHelper - Browser extension to download videos from the Web
WebTube - Lightweight YouTube frontend
youtube-dl-gui - A cross platform front-end GUI of the popular youtube-dl written in wxPython.
LiteTube - LiteTube is an app that provides HQ video and audio streaming players.
Youtube Video and Audio Downloader - Download YouTube videos in all available formats and extract the original audio files.