My Disk Cleaner is a free system maintenance tool. It can scan your hard drives and clean them to speed them up. Although the application is free to download and install, the interesting features only become available through in-app purchases (IAP). Without those IAPs the application can only carry out cleaning operations for unused files or other files that you probably don't need in your system.
When you first launch the application, you will see a list of your mounted volumes on the left pane. You can select any of those and start a drive scan by clicking on the "scan" button at the top. After the scan is complete, you will see a list of those files or folders that the app can clean app for you.
If you purchase the "pro" features, you will also be able to scan for duplicate files, sort the found files by size, and customize the scanning process so that it takes less time to complete. Perhaps that is one of the biggest problems with this app: it is incredibly slow. It took over 2 hours to scan a 500-gigabyte disk. I also noticed that the application can't scan your Mac's internal hard drive because it doesn't have the necessary privileges. This might be to prevent corrupting your operating system.
In short, the utter slowness and the inability to scan your home drive prevent me from recommending this application for hard drive cleaning operations.