A simple menubar app for tracking your application usage

Groups of applications can be created in the "Show all" window
Recordings can be deleted in the "Show all" window
Your tracking data is saved on your Mac only

Itsycal is a tiny menu bar calendar.

If you want, it will display your events as a companion to the Mac Calendar app. You can also create and delete (but not edit) events.

ImDisk Toolkit

Use AirPlay to stream to UPnP/Sonos & Chromecast devices

Ncdu is a disk usage analyzer with an ncurses interface. It is designed to find space hogs on a remote server where you don't have an entire graphical setup available, but it is a useful tool even on regular desktop systems. Ncdu aims to be fast, simple and easy to use, and should be able to run in any minimal POSIX-like environment with ncurses installed.

Simplified and community-driven man pages