I'm a huge fan of ngrok, a tool that allows you to open a secure tunnel from your machine to the outside world to enable testing APIs and things. Mostly I use virtual machines for development, but by default the ngrok dashboard is only available when requested from the machine that ngrok is running on ... and I want to be able to see the web interface from my host machine.

This is a config setting but it can't be supplied on the command line, instead create a file called ~/.ngrok2/ngrok.yml and add the following line:

web_addr: 0.0.0.0:4040

This will enable you to then reach the web interface at [VM IP or hostname]:4040.