Please make sure that you add your user to the webcamd group after the installation of the dependencies, this can be done by running doas pw groupmod webcamd -m $USER
You will also want to enable webcamd and the cuse module to load at boot for that you'll need to modify /etc/rc.conf and /boot/loader.conf with:
webcamd_enable="YES"
and
cuse_load="YES"
respectively.
Run doas pkg install gmake gcc pkgconf libjpeg-turbo usbmuxd libusbmuxd alsa-lib v4l_compat speex ffmpeg webcamd libappindicator
Run gmake, or gmake droidcam-cli if you wish to only build the command line version of droidcam.
To install, run doas ./install-client
You'll need to run doas webcamd -B -c v4l2loopback before launching droidcam