Built this out of my self-hosted VPS setup. Covers local and remote forwarding, the GatewayPorts gotcha, bastion hosts, and why ngrok is essentially just remote port forwarding with a reverse proxy in front.
I love the idea! It just creates a very minimalistic feeling and helps my mind not get overwhelmed with big chunks of text. However, the no-edits thing is a bit frustrating personally. A solution would be to allow edits as long as the text is visible, plus increase the timeline the text stays in the view (the pace in the homepage is ideal i feel).