Video Conferencing is a function that to my knowledge is not currently available as a Portable App. I use Logitech Vid on the SightSpeed network to videoconference with my family. I am unable to install this app in my company tablet computer which has a built in camera.
I am sure that I am not the only person who has this situation.
Putting the APP on a USB drive so that it does not corrupt any data on the portable tablet computer and does not modify the registry on that machine would be very useful.