My girlfriend has the iPhone 4 while I have the iPhone 5 and we noticed that the versions of Facebook seem very different though both are running the lates version of the Facebook app and the latest iOS. My iPhone 5 still has the button at the top left top pop out that side menu and I have the new chat heads. However her iPhone 4 is missing the button to pop out the side menu and instead has a bar at the bottom of the screen with several of the options that were I'm the pop out menu. Her iPhone 4 also doesn't have the chat heads. Anyone else notice how the iPhone 4 version of the Facebook app is very different and wonder why it is this way?