mackeeper software in 2019

Never install any app the claims to "clean", "tune up" or "speed up" your Mac. They are all quite unnecessary and exist only to separate the unwary from their cash. Worse, in inexperienced hands they can do considerable damage to a Mac OS installation and lead to significant dataloss.

Truly, avoid like the plague.

Keep away from it "as if it were a swarm of bees."

Read: Effective defenses against malware and other threats - Apple Community for further details.