iMac Cleaner

Any Third Party Applications that will interfere with the normal operation of the OS,  is an invitation for disaster and comprise the Operating System

Certain Applications maybe available on the Apple Apps Store - this only means the Developer is prepared to pay Apple a portion on each sale. What the Application may do to the computer is up to the User to check this out before purchase

Any of the below should be removed as per Developers Instructions 

1 - Disk Cleaner 

This will include CleanMyMac , aka “ BrickMyMac “

MacKeeper,

Dr Cleaner Pro Plus

Open Cleaner one Pro

Macmechanic

Read some of the posting and arrive at your own conclusions.

I would not let any of the above Applications near any of my 4 Machines ever.

Non-Apple "cleaning" apps are scams.

If you are having trouble with your Mac, describe what it is. Start from the beginning — is it working slowly, are you getting low on storage space...? Etc.

Please determine if the same problems occur in "Safe Mode": How to use safe mode on your Mac - Apple Support.