Browser: Firefox 31 (build after 2014-05-11) and higher:
* No add-on needed. Preference ''dom.mozApps.use_reviewer_certs'' must be created and set to ''true'' in about:config. NOTE: case sensitive preference name - dom is often (mis-)corrected to Dom.
== Other helpful tools ==
* App manager: https://developer.mozilla.org/en-US/Firefox_OS/Using_the_App_Manager
* Firewatch: https://github.com/digitarald/firewatch