ZetaWatch - Manage ZFS volumes in the menu bar
ncdu - A disk usage analyzer with an ncurses interface, aimed to be run on a remote server where you...
Baobab - Distributor of workload automation, financial statement reporting, data access, IT Asset Management and Service Desk software solutions.
WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Filelight - Filelight is an application to visualize the disk usage on your computer.
Free Disk Space Monitor - Status bar app for macOS that shows the amount of free disk space left on the hard drive.