Hi! That's what we are building for at Kommu!

Kommu is a mobile-first social network that allows users to (1) discover and coordinate travel with friends and connections, and (2) propose home exchanges within their personal trusted circles to travel more affordably.

We are prepping to launch by EOY, but if you sign up for the waitlist (gokommu.com) then you can apply to join the members Slack group where friends of friends are actively listing places for swaps and exchanges.