I’m unsure if it can add an SD card, but it does add a lot of battery. I’ve wanted the camera-case since I got the phone, but my phone lives in my pocket most of the time, and can’t quite justify if I’m going to use the features/extra battery just yet.
I’ve only just setup a proper Skydrive/Onedrive account (1TB with Office 365 win), it had completely slipped my mind to start using that 
Large online storage is always fun with my lowly Australian internet speeds.