Hah, I was dealing with this problem today.

My approach: Add entries for my localhost apps to `/etc/hosts`, and set up nginx as a reverse proxy.

Now when I go to `http://myapp.local` in the browser, `/etc/hosts` tells it to go to `localhost:80`. The http server sitting there knows which port to send the request to. I also made a systemd service that starts nginx automatically.

Now I have meaningful URLs for local apps, and I don't have to remember which one is listening on which port.