•  Mozilla plans to launch support for an open ecosystem of extensions in Firefox for Android at addons.mozilla.org. 

•  Firefox will be the only major Android browser to support an open ecosystem of extensions. 

•  Mozilla has created an infrastructure to support extensions in Firefox for Android. 

•  Mozilla is planning additional events and resources to support extension developers. 

•  Extensions are no longer hosted in the main process of Firefox for Android, improving stability. 

•  Developers are encouraged to update the manifest.json background key and use non-persistent event pages. 

•  Developers can join the Firefox Add-ons discussion to gain community support and contribute. 

Finally. I've been using IceRaven for Android Firefox Addon support. An official client would be nice.