I agree that Vagrant would be an all-purpose solution. However it may be a bit TOO much if you just want the wifi part (it’s not super beginner easy to set up and such, and takes a little bit to get used to).
Have you tried Prepros? Although it’s mainly a tool for preprocessing Sass and LESS and all that, it also has a built-in webserver. I’m not 100% sure, but I believe it can generate a URL (based on the computer’s IP address) that you can access from any computer on the same network. You can develop a site on your Mac and you can view it on another computer or phone or tablet or anything.