Social network users can expect richer experience with major updates to both Android and iPhone applications for Facebook, as well as with the launch of the “single sign on” feature for mobile apps.
When one is logged into Facebook, it's easier to log into other apps on the mobile phone with single sign on.
When first logged in to the Facebook application on the mobile phone, the user can log in to any other application on the phone that supports single sign on without typing a username or password again.
This works on any Android phone or any iPhone, iPad or iPod Touch device that supports multitasking (most iOS4 devices).