The iPhone app doesn’t have all the features that everyone wants right now, namely the ability to write on peoples’ walls. The application will update automatically as Facebook rolls out more features in the future.
I’m waiting for the ability to write on walls, to have a complete feed update, and to view pictures better. For myself the web app is so much better at this point.
It will be downloaded automatically to your iPhone through the App Store. You don’t need to worry about doing anything. A badge will appear on the App Store icon (a number in a red circle, similar to the way you are notified about new email and SMS messages) which indicates that updates are available for some or more applications. Tap on the App Store and you will be taken to the updates section, where you can choose to update applications.
MySpace has taken a great step, but I don’t like the graphics that much. Could use better interface. Don’t get me wrong it’s the best app for myspace ever. It can use a little work though.