TinyWall - Lightweight and non-intrusive firewall
Emsisoft Online Armor Firewall - Emsisoft Online Armor Firewall is a freemium online firewall protection system by the Emsisoft that is based on the own independent protection technology of the Emsisoft.
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...
ufw - Ufw stands for Uncomplicated Firewall, and is program for managing a netfilter firewall.
Windows Firewall Control - Windows Firewall Control is not the built in firewall system in the Windows operating systems.
Little Snitch - Little Snitch is a firewall application that monitors and controls outbound internet traffic.