WebTube - Lightweight YouTube frontend

YouTube Messenger - YouTube in-app video sharing and messaging

Minimize play in background - This all-in-one application for android allows you to watch all videos while using a smartphone.

Kiwi Music Player - Listen to any track on youtube on this Mac App

8player Lite - 8player Lite lets you play movies and music from your phone or tablet on your Apple TV with features such as multiple library support, more file formats, subtitle support, and AirPlay.

YouTube Vanced - Vanced is a modded version of YouTube with many features such as adblocking and background playback