Finally! The Terminal command did fail to block MacKeeper & affiliated junk sites (incl. the http://www.apple.com-macbook-protect.systems/mackeeper/…). It's, by the way, beyond Me that MacKeeper crooks and their affiliates haven't been made to rot in jail, but that's off-topic.
There are some Chrome, FireFox, etc. extensions that do block websites, including the malicious crap-sites in question, but Safari, unfortunately, to this day cannot do it. Again, makes you ponder…
Cisdem's AppCrypt, upon the other hand, DOES do the trick!. Bravo, Cisdem!
I also applaud your relatively reasonably priced lifetime update policy.
Now, please, Cisdem, do polish up the interface, including the [ugly] menu & app icons, buttons and the rest of the GUI!
Also, a support for fingerprint authentication (both touchID in newer MacBook Pros and iOS unlock via apps such as the MacID / Unlox, etc. for Macs without a TouchID - would be much appreciated.
Hence, 4 stars instead of 5.