slackbuilds/system/usbmuxd

usbmuxd: USB Multiplex Daemon. This bit of software is in charge of
talking to your iPhone or iPod Touch over USB and coordinating access to
its services by other applications.

Create a usbmux user with:
  useradd -u 233 -g plugdev -d /dev/null -s /bin/false usbmux

Requires: libusb1