Does the latest version of MacKeeper work with ElCapitan? I bought a new computer, and my old Mavericks MacKeeper didn't seem to work. Is the application upgraded now for ElCapitan, please?
The only way to see if the application is compatible with El Capitan is to test it using the available download from the official website.
I've checked all the pages on its home URL and I didn't find anything related to system requirements.
Note: As a personal note, I advise staying away from MacKeeper since it's considered to be a scam by many users.