Firefox for mobile is a web browser for mobile phones, tablets, and PDAs. It was originally first released for the Nokia Maemo operating system, specifically the Nokia N900, on January 28, 2010. On March 29, 2011, an Android version was released, being based on version 4. With the release of the mobile version, the browser's version number was bumped from 2 to 4, synchronizing it with all future desktop releases of Firefox because the rendering engines used in both browsers are the same. Version 7 was the last release for Maemo on the N900.