WordPress for Firefox OS was started in the Summer of 2013 by Sayak Sarkar as a Google Summer of Code project. The app is based on WordPress for webOS, but adapted for smaller screens and styled to be more consistent with WordPress for Android.
To get started you will need a copy of the Firefox OS Simulator, a clone of this repository, and your favorite text editor - Firefox OS apps are built with HTML, CSS, and JavaScript.
To test the app, launch the Firefox OS Simulator from the Firefox Tools > Web Developer > Firefox OS Simulator menu and add the project directory to the Simulator.