My Galaxy S4, @ 6 months old, kept saying it could not detect the SIM card. ATT removed and restarted it and said all should be good. 2 hours later it did it again. Went back next day, put a NEW SIM card in it, and same thing a few hours later. They sent me a replacement phone, but since I purchased this phone mainly for the great camera, and I am not tech savvy , what all will I lose when I switch to my new phone? I know I will lose pictures because the ATT rep that sold it to me said it had an SD card in it, but it does not. But I always download those to my PC, so no big deal there. I would like to take my home screen / screensaver pic and put it back on my phone. BUT, mainly I need to know if I will lose my contacts? Any downloaded apps? ALSO, what do I need to remove (other than the SIM card) to make it safe for my old phone to be sent back to ATT, as far as privacy/ identity etc?