Windows and macOS have similar clients (Hass.Agent for Windows and Home Assistant for macOS).
I’ve found these kinds of clients useful because I can remotely wake-up or sleep computers, track how long they are turned on for, and automatically pause my lights and music when my webcam turns on.
There’s a set of special topics under
homeassistant/
that devices also publish to that describe what each topic does and how HA should present it. HA will subscribe to everything under that root topic to discover all your MQTT devices.