CleanMyMac X - Clean, protect and speed up your Mac
Recuva - Accidentally deleted an important file? Lost files after a computer crash?
DaisyDisk - DaisyDisk is a disk analyzer tool for OS X that visualizes hard disk usage and allows to free up hard disk space.
TestDisk - TestDisk is a free and open source data recovery software tool designed to recover lost partition and unerase deleted files. DownloadDownload TestDisk & PhotoRec. TestDisk is a free and open .
Fossils - Find and clean out all your old unused files
EaseUS Data Recovery Wizard - Advanced data recovery software to do format recovery, unformat and recover deleted files emptied...