https

Cloudflare Quick Tunnels provide a free and secure way to deploy local applications to the internet instantly using a single command, with automatic HTTPS and DDoS protection via Cloudflare's global network.

Slim is a minimalist command-line tool that converts local ports into clean HTTPS domains (e.g., myapp.test) with one command. It also supports intranet penetration to generate public links for collaborative debugging and demos. It's completely free and open source.

Troy Hunt's weekly podcast episode with Scott Helme, where they launch 'Why no Passkeys?', a successor to 'Why no HTTPS?' that encourages organizations to adopt passkeys for authentication.

NetworkSpy is an HTTP(s) proxy debugger with a custom viewer, aimed at developers for inspecting network traffic.