Chrome Remote Desktop - Access your desktop from another device. Punches through firewalls and routers automatically.
Unfortunately, it does that by making Google a 3rd party(I think that they even handle the authentication) in every connection you make between two of your own computers. They aren't privy to the actual content of the interaction, to the best of my knowledge; but that still creeps me the hell out.
It's unfortunate, really. An architecturally-modern successor to VNC(ie. same platform-agnostic low level approach; but taking advantage of the fact that most devices can, often with dedicated coprocessors, pump out a very nice H.264 stream or similar as easily or more easily than retro JPEG tiling stuff, along with a dose of some sort of remotely modern authentication) would be fantastic; but CRD doesn't even offer a 'the host is right on the same damn subnet, no, I don't need Google looking over my shoulder to connect to it!' mode.
"Show business is just like high school, except you get paid." - Martin Mull