The new Firefox OS reference phone. Following on a busy Mobile World Congress last year, Mozilla is again showcasing the evolution of its Firefox OS in Barcelona.  

The company has announced a 4.5-inch dual-core reference phone, as well as a number of new tools for developers to create and test their designs for the Web-based mobile platform.

The new reference phone is called the Firefox OS Flame. It includes a 1.2GHZ dual-core Snapdragon processor, 5 megapixel rear-facing camera, 8GB of internal storage, as well as a 1,800 mAh battery. The phone is a big step up from previous developer devices. 

Mozilla also announced a new integration with PhoneGap, which the company says will PhoneGap developers to port their existing apps to Firefox OS in a matter of hours, while new WebAPIs will continue to narrow the gap between native and Web apps. At Mobile World Congress, Mozilla also launched developer tools that will allow OEMs and operators to easily customize Firefox OS for a variety of customer segments.

In an effort to further enabled developers, Mozilla introduced App Manager, which brings the Firefox Web developer tools to mobile app developers. The company also introduced new WebAPIsm, including WebNFC and Data Store API. The new APIs will allow developers to add addtional functionality to their applications.

Mozilla is also hoping to expand Firefox OS into the realm of tablets. The company recently introduced a tablet contribution program aimed at accelerating the build of Firefox OS for tablets and its supporting ecosystem, with Foxconn as the first hardware partner.

As part of the Firefox OS tablet contribution program, VIA is offering a 7-inch Vixen reference tablet for developers around the world to help the Mozilla community complete the build of Firefox OS for tablets. Developers can now apply to be a part of this program. 

There will be a 7- and 10-inch reference tablet designs. The 10-inch slate includes a 1 GHz quad-core, 2GB of RAM and a 5-megapixel camera. 

Mozilla's Firefox OS made a splash at last year's Mobile World Congress, when the company announced 18 carrier partners putting their weight behind the new web-based OS, as well as initial devices from Alcatel OneTouch, ZTE and LG, with Huawei to follow.