howmanypeoplearearound “calculates the number of people in the vicinity using the approximate number of smartphones as a proxy”
To do this on Mac os X first make sure that you have “brew” installed.
See the simple instructions / site hear
https://brew.sh/
Your also going to need tshark the cli version of wireshark installed
brew install tshark
Also I found using python3 important as I was having dependency problems with the standard python install
Download and install python3 from hear
https://www.python.org/downloads/mac-osx/
Then
sudo pip3 install howmanypeoplearearound
now you can observe howmanypeoplearearound !
Typical usage
sudo howmanypeoplearearound -s 300 -o scan_big2.json -a en1
(Listens to network traffic for 5 minutes writes to the file scan_big2.json in json format using interface en1 (wireless card use ifconfig -a to check that yours is named in the same manner)