Ask HN: What are some services to forward traffic to my firewalled dev machine?

I'm looking for a service that offers a publicly accessible domain name that I can have forward traffic to my laptop when my laptop behind a firewall that I don't control. (Think demoing a website to a client while working from a coffee shop.) I know I can set this up with my own VPS and SSH -R, but I'd rather just pay somebody else to keep the VPS working and secured. I'd prefer to use plain ssh to connect to the service and have a custom subdomain (rather than a custom port), but neither of these are deal breakers. I know services exist for this but I can't remember the names of any of them and my google-fu is failing me. Any links and experiences would be appreciated.