Facebook iOS app gets a facelift@ 2013/09/19
And, each of those tabs saves your state, so if you've scrolled down a ways in your feed, then do some messaging and come back, you won't have to roll through all the content you've already viewed. This function also transforms the More screen into a personally customizeable tab, as the app remembers whatever option you last chose. While this new option is a departure from the left-side nav users have grown accustomed to, the changes are very much made with you in mind. Developers went through 100 variants of the app tested by between 5-10 million users -- who wanted less friction in the UI -- and that feedback informed the redesign. Keep in mind, however, that iPad owners won't be getting this new nav (Facebook found that the existing UI was better suited to the larger screen).
As for the iOS 7 paint job? Highlights include wireframe icons and a translucent nav bar at the top of the screen that allows underlying content to bleed through, along with a general flattening of the app's appearance. However, users will only see this new look if they have upgraded to iOS 7. Folks sticking with iOS 5 and 6 will still get the new tabbed nav functionality, but the aesthetics will remain in line with the rest of their device's appearance. Wanna give the new Facebook a try? You know what to do.