The Facebook app for iPhone allows you to access many of the functions of the Facebook social networking website over an EDGE, 3G, or Wi-Fi. Supported functions include reading news feeds and walls along with comments, reading profiles, flipping through photo galleries, browsing your friends list, reading and sending messages, and instant messaging.

On August 27th, 2009 Apple approved the 3.0 update to Facebook for the iPhone. It's a free update. Features supported in the new version include landscape mode, Events, Pages, birthdays, Notes, photo albums, photo zooming, photo tagging, uploading videos from the iPhone 3GS, changing your profile pic, "Like," a built-in web browser, browsing friends of friends and mutual friends, adding new friends, a news feed more like the web one, calling and texting friends from within the app, and friend and page shortcuts.