I currently use TinyWall Firewall, it works very well, it’s small/portable, no complaints I even donated to the Dev but I would really prefer open source, also it needs to be user friendly like TinyWall so my non-tech family members can/will use it like they do with TinyWall.
This. There really is no point in installing something like tinywall, when there is a built in firewall that has more functionality (granted its much less user friendly).