Sadly there is no other FOSS out there that combines remote support with good NAT traversal. Existing remote access tools such e.g. VNC all do not offer NAT traversal and are incredibly hard to setup. All FOSS web/phone conference tools offering screen sharing refuse to implement transferring Cursor/Keyboard control. Probably because it is not so easy, but mostly, I guess, out if fear for diffuse security problems.
Too bad people then will be compelled to use this absolute mess...