Clean Master is a free app available on Google Play Store that helps to free up space and improve performance on Android devices. It scans for junk files, cached data, and other unnecessary files and provides a complete breakdown of all the files it wants to delete. The app also offers advanced options for additional cleaning. However, the app is filled with adverts and sponsored content, making it a UI nightmare. The main icons on the app include Junk Files, Phone Boost, Antivirus, and App Manager, along with a quick overview of available RAM and storage space.