NetstatPlus 1.6 for Mac could be downloaded from the developer's website when we last checked. We cannot confirm if there is a free download of this app available.
Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. The actual developer of this free software for Mac is Boolean Candy Pty Ltd. The application lies within Internet & Network Tools, more precisely Network tools.
From the developer:
NetstatPlus is a GUI app that displays the status of TCP network connections on your Mac, similarly to the netstat command line program. NetstatPlus is an essential update for the netstat command line tool. It lets you quickly understand the status of TCP connections on your Mac by updating the connection information automatically, with resizable columns to show long DNS names, and protocol decoding by port number.
You may want to check out more Mac applications, such as Flame, AirGrab Network Packet Analyzer or NetStatInDock, which might be related to NetstatPlus.