Adding an extra security layer to the system can be more thicken with another Objective-see security tools (Knock-knock, Block-block, Ransomwhere, Netiquette).
Do not use this software if you are running Mojave ON A macBook it will stop your computer firing up and the fix is as rubbish as the software. Gives open source software a really bad name. Had I not just backed up a few hours before I'd have been stuffed as had to wipe hard drive and reload. WARNING REALLY BAD SOFTWARE NO JOKE!!!
Heard about on iOS today from Leo, I installed on my 2018 Mac mini that has worked flawlessly for 6 months. Has caused all kinds of problems since installing. I have uninstalled but still having problems after Mac wakes up! I would NOT recommend!!!!! It might be free, I would rather pay something instead of having issues now. I am getting Kernel error messages randomly.
Why pay for others, when you can have this one for free, and is even better than the others? It does the job well and is better because, unlike Little Snitch, etc., I do not get bombarded with dozens of warnings about the same app, with more than one option (servers, ports, etc.). With Lulu, when you click block, all connections of that app are blocked. Nice!