This plugin does still offer some additional functionality, such as the CLI, chamfers and unit conversion. The plugin is no longer worthwhile maintaining.
KiCAD PcbNew Plugin and CLI to automatically apply a rounded fillet of a given radius to all board edges of a PCB.
The plugin can be installed by downloading the latest release and installing with the KiCAD Package Content Manager (PCM) with Install from file option.
Ki-Fillet also offers a Command-Line Interface (CLI) to perform filleting actions. You should clone this repository and use the standlone script kifillet.py to access the CLI (PyPi package coming soon!).
You can view the help of the interface by calling python PATH/TO/kifillet/kifillet.py --help.