I haven't checked in on them lately but it's by the crew I worked with on Dat and Beaker. I tried the early demo and thought they did a great job with the application, and I know they've continued to make break-throughs on the hole-punching tech (in fact they rebranded to Holepunch).

They're really talented folks so if you have any interested in p2p comms, I'd give them a look. https://keet.io