Skype
From wikinotes
Skype is fairly self explanatory. It used to have external dependencies like cheese,
but they all seem to have been incorporated into the base-package.
Skype requires pulseaudio, or apulse (pulseaudio emulator).
Skype has become known as a dangerous program, it provides a constant stream of encrypted data back to microsoft, even when it is not running. You may want to install it in a VM, or with AppArmour.