Seeking a good security app

You may wish to browse these resources which will indicate why you probably don't need an app for this. If you are indeed one of the rich and famous who might need specific security then you should probably contact a security consultant.

Apple Platform Security - Apple Support

Get help with security issues - Apple Support

https://security.apple.com/blog/memory-integrity-enforcement/

My impression is the weakest part of security is the behavior of individuals themselves falling for scams and phishing and no app can protect against that. Be smart.

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

Apple devices already has built-in security in all of their devices. Most people in the community would probably agree that additional apps (with the exception of enterprise solutions) is unnecessary for the security of your device.

To learn more, here is a good article.

Effective defenses against malware and ot… - Apple Community

What are you trying to secure or achieve? As StanleyG. states, additional security applications unnecessary on Apple's platforms. I will go further and suggest that the majority of "security" applications installed are marketing nonsense at best, but have the real likelihood to instead reduce your devices security, stability, performance, and privacy.