TinyWall - Lightweight and non-intrusive firewall
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...
Windows 10 Firewall Control - Windows 10 Firewall Control: simple and exhaustive solution for applications network activity controlling and monitoring.
Fing Desktop - Device discovery and network monitoring
Windows Firewall Control - Windows Firewall Control is not the built in firewall system in the Windows operating systems.
Radio Silence - Radio Silence is a network monitor and firewall for the macOS. The software stops apps from making network connections. The firewall runs in the background and does not require an open window.