Parental controls

I would like to be able to have any ability to add new podcasts to my feed protected by a password, like a parental control type thing. I’ve yet to find such a feature in any podcast app and I personally know several people who would use such a thing to allow their kids (or to control themselves) to listen to specific podcasts only.
Admittedly I don’t know the first thing about coding or app development, so I have no idea how hard it would be to make such a thing, but it is a feature I feel would be quite valuable and would gain many users.