By Dan Whitworth
It's hoped the latest version will have fewer glitches than before
The latest version of Facebook for Apple's iPhone has gone live.
The original application arrived in the summer of 2008, with a further update - Facebook 2.0 - becoming available in September.
Its creators say the latest 2.1 version has made significant improvements on previous incarnations.
These include fewer crashes, quicker synch times and fixing bugs - including one which sometimes caused the screen to go blank.
It's already one of the most popular applications for the iPhone, with 4.5 million users having made the most of the fact that it's free to download. But some users say it can still crash.
The trend of using Facebook on mobiles is growing.
The site's Chief Operating Officer Sheryl Sandberg says more than 20 million people now use them to get access to it.