WinDirStat - WinDirStat is a disk usage statistics viewer and cleanup tool, inspired by KDirStat.
Hidden Bar - A ultra-light MacOS utility that helps hide menu bar icons.
TreeSize - TreeSize tells you where precious disk space has gone to.
Bartender Mac App - Bartender is an award-winning app for macOS that superpowers your menu bar, giving you total control over your menu bar items, what's displayed, and when, with menu bar items only showing when you need them.
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.
Vanilla - Vanilla is a free Mac app that lets you hide icons from your menu bar.