Firewalld is described as 'Provides a dynamically managed firewall with support for network/firewall zones that define the trust level of network connections or interfaces. It has support for IPv4, IPv6 firewall settings, ethernet bridges and IP sets' and is a Firewall in the security & privacy category. There are more than 10 alternatives to Firewalld for a variety of platforms, including Linux, Windows, Mac, Android and F-Droid apps. The best Firewalld alternative is Portmaster, which is both free and Open Source. Other great apps like Firewalld are simplewall, RethinkDNS, Fort Firewall and NetGuard.