WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
IceCream - Free up space fast and never miss a moment again
TreeSize - TreeSize tells you where precious disk space has gone to.
Cisdem iPhoneCleaner - Safe iPhone cleaner to clean iPhone, iPad, iPod touch junks to free up space and backup iPhone Mac.
SpaceSniffer - SpaceSniffer is a freeWare (donations are welcome) and portable tool application that lets you understand how folders and files are structured on your disks.
iMyfone Umate - iMyfone Umate is an iPhone space saver which helps iPhone/iPad/iPod touch users free up iPhone...