LuLu is the free, shared-source firewall for macOS. Its goal is simple; block any unknown outgoing connections, until approved by the user. While it was designed to generically detect malware by flagging unauthorized networking connections, LuLu can also be used to block OS...
LuLu by Objective-See vs Little Snitch opinions
Free (Libre) Software is and will be always best for the humanity :)
I Wanted a tool to replace Little Snitch, and this one is GREAT. It is Free, Open Source, and very lite weight.
It's very simple and free!
GlassWire is a network security monitoring tool and analyzer that visualizes your network activity on an easy to use graph, alerts you of possible threats, manages your firewall, and more.
GlassWire vs Little Snitch opinions
Good software, reputable developers and it has even more features than Little Snitch.
Portmaster is a free and open-source application firewall that puts you back in charge over all your computer's network connections.
NetLimiter is an ultimate Internet traffic control and monitoring tool designed for Windows. You can use NetLimiter to set download/upload transfer rate limits for applications or even single connection and monitor their Internet traffic.
NetLimiter vs Little Snitch opinions
The ltest version makes it impossible to block Windows System and Windows Apps.
NWO is collecting data on us...
Windows Firewall Control is a powerful tool that extends the functionality of the Windows Firewall and provides new extra features that make Windows Firewall better. It runs in the system tray and allows the user to control the native firewall easily without having to waste time...
It lists activities, broadcast receivers, services, providers, permissions, signatures, shared libraries, etc. of any app