Rated 5 out of 5 stars
Very, very good!!
If you can do an example (tutorial) for programming of app, it were very, very, very good :D
There are tutorials and other documentation at the <a href="https://marketplace.firefox.com/developers/">Firefox Marketplace Developer Hub</a>, and there's a <a href="https://developer.mozilla.org/en-US/docs/Tools/Firefox_OS_Simulator/Simulator_Walkthrough">Simulator tutorial on MDN</a>.