How to Download the Facebook Application for the iPhone
Facebook is a popular social networking site which allows you to keep in contact with friends and co-workers, share status updates, upload pictures, and instant message with contacts. If you have an iPhone then downloading the Facebook for iPhone application can allow you to do everything you want to do on Facebook quickly while you're on-the-go.
Things You'll Need
Click on the "App Store" icon on your iPhone's home screen.
Search the App Store for "Facebook."
Select the "Facebook" application from the choices that appear.
Click on the button on the top right side of the screen that says "Free."
Click on the green button that says "Install" that appears in the place where "Free" once was.
Enter your iTunes password when prompted and click "ok"
Wait for the status bar to complete fill on the Facebook icon that shows up on your home screen. Once the status bar disappears your application will be ready to use.