FacePause - Look away to pause YouTube videos
Lark Player - Lark Player – YouTube Music & Free MP3 Top Player is a fine tool developed by Mobiuspace Tech Top Player.
reEmbed - Custom YouTube Video Player
Audiomack - The free SoundCloud alternative
TabFloater - Browser extension to use picture-in-picture with any website
Musicolet - Musicolet is a small yet feature-rich offline Music Player for Android.