droidcam : Use your phone or tablet as webcam with a v4l device driver and app ( https://www.dev47apps.com/droidcam/linux/ )
v4l2loopback : v4l2 loopback device whose output is its own input ( https://github.com/umlaeute/v4l2loopback )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a natinst
For Paludis use this rsync : rsync://gentoo.zugaina.org/natinst-portage
If you have a problem : ycarus(-at-)zugaina.org