How to Save Facebook Photos to Your iPhone Camera Roll Using the Official Facebook for iPhone App [Jailbreak Tweak]
One of the features missing from the official Facebook for iPhone app is the ability to save to your Facebook photos to iPhone’s camera roll. But fortunately, there is now a new iPhone tweak available on Cydia which enables you to save any photo from the Facebook app right into camera roll.
Available by the name of FBPhotoSave, this tweak allows you to save photos by using simple gestures. All you have to do is to tap and hold the picture which you want to save until it prompts you to save it to the camera roll, as also illustrated by the screenshots below.