@jsummer I have one, its not really very privacy friendly sadly. You could run NetGuard 24/7 to block all internet traffic, but that would drain battery and I don't personally do that.

Check out my camera blocking app at: https://glitcher32.com/camerablocker

and this screenshot blocker:
https://schiffer.tech/screenwings-mobile.html

Also checkout
PilferShush Jammer om F-Droid to block microphone.

If you need any help with anything let me know.