1) Zenmap is the official Nmap Security Scanner GUI. It can be used on a number of different platforms including Windows, Mac OS X, Linux, etc. Zenmap is a free application with its goal to make Nmap easy for beginners to use, while also providing many different advanced features for experienced Nmap users.
2) I installed Zenmap on a 2010 MacBook running mac OS High Sierra 10.13.6.
3) I did not run into any problems while using Zenmap, I found the application to be quite easy to use and understand while scanning different networks.
4) From running scans in Zenmap, the things that I learned about my network is that there is 1 IP address with one host up, the host that is up has a latency of 0.000032 seconds, and that there are 99 closed ports