"Quickly and effectively remove unused or temporary files, unwanted cookies, and other unneeded files from applications." Chosen for Gizmo's 9 great freeware.
Additionally, it can scan the registry for issues, erase, manage the startup, uninstall, and clean system restore points.
Related: Also runs automatically at startup or as a task.
What's it for? - Over time unnecessary files accumulate, which can be removed with a disk cleaner to maintain system performance.