A short, echo-y (I'm pretty sure that's not a word) show & tell video in my shower. I'd have done away with the echo, but, you know...we're in a shower.
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app