Terminal disk-space navigator
Given a path on your hard-drive (which could also be the root path, i.e. /). diskonaut scans it and indexes its metadata to memory so that you could explore its contents (even while still scanning!). Once completed, you can navigate through subfolders, getting a visual treemap representation of what's taking up your disk space. You can even delete files or folders and diskonaut will track how much space you've freed up in this session.
To install diskonaut, paste this in macOS terminal after installing MacPorts
sudo port install diskonaut