How to: Basics of Using Safing Portmaster | Avoid the Hack (avoidthehack!)
NetGuard
Tracker-control-android: TrackerControl Android: monitor and control trackers and ads.
AdAway
LuLu
ufw in Launchpad
Rule Language | USBGuard
Draeneg, it's time to regain control of your data privacy!
How to: Basics of Using Safing Portmaster | avoidthehack!
Fail2ban (Español) - ArchWiki
Instalar configurar y usar fail2ban para evitar ataques de fuerza bruta
UFW Essentials: Common Firewall Rules and Commands
Iptables Essentials: Common Firewall Rules and Commands
RethinkDNS | Fast, secure, configurable, private DNS + Firewall for Android.
Safing - Love Freedom