NetworkManager-ssh
https://github.com/danfruehauf/NetworkManager-ssh
SSH is great for setting up quick tunnels with minimal effort, its basically a plugin to network manager.
Yes its open source GPL-2
Not sure how many users but its very handy for businesses
source tarball is here
https://github.com/danfruehauf/NetworkManager-ssh/archive/1.2.8.tar.gz