Now to find a free ad blocker for mobile. Only tried briefly other day and still got intro ads. Didn't stick with it longer to see if the others were out, but suspect they were since app wants money for enhanced function, and wording doesn't even imply it works in app necessarily (sounded like web only)
Discussion
Mullvad iOS app does it well with the dns blockers settings (not free). Would remove apps in browser.
Brave browser iOS (free) does pip and no ads. But you have to play from brave not yt app.
Tube pip obviously (free)
Not sure you can remove from yt app without paying
