The Facebook app for iPhone and iPad has been updated to version 5.6 and the major new feature is simple yet convenient -- you can now set cover photos on the go, right from your iOS device. If that's not enough, Facebook has also reduced the amount of taps it takes to start a group message.
To change your cover photo inside the Facebook iOS app, simply touch and hold the existing photo, and a slide-up menu will give you the option to take a new one, or select and existing photo from your Camera Roll.
I tried it out on my account and it worked easily and quickly. If you give it a whirl, let me know how it works for you.
You can grab the Facebook for iPhone and iPad app from the App Store.