FirefoxOS is a simple concept - every app is an Open Web App.

As of now FirefoxOS is stable and running on quite a few cool devices like this huge panasonic TV or this cool transparent high end Japanese phone.

Find a device for you or look at all devices

Building apps

Creating apps for FirefoxOS is as simple as creating a website in html. Because that is exactly what FirefoxOS apps are - webpages with access to phone features.

Read more about building Open Web Apps