Do you want to play youtube in the background in Android or ISO iPhone?
The official youtube app doesn't support the background video play.
In this video, i will show you a life hack way to play youtube in the background without any application or software, without Root or jailbreak. It's very easy way, no any difficulty. Background Stream. No need of Youtube red.
In this secret, i am using Google Chrome to playing and listening in the background even when the screen is locked.