NetGuard - NetGuard
TinyWall - Lightweight and non-intrusive firewall
AFWall+ - AFWall+ (Android Firewall +) - iptables based firewall for Android
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...
NoRoot Firewall - Firewall WITHOUT ROOT.
Windows Firewall Control - Windows Firewall Control is not the built in firewall system in the Windows operating systems.