Thanks for the reply. Why does a factory reset erase the sd card? The whole point of saving the apps or anything there for that matter is to have them after a reset. I still have my contacts that I saved there.
This is a common misconception when it comes to the whole idea of moving apps to the SD card.
The primary purpose behind moving apps to SD storage is to reduce the amount of data saved to the internal data partition. Even when moving apps to SD card, all you are really moving is the
data used by the app, the apps itself still needs to be installed on phone, and configured with the correct symbolic links to know where to pull it's data from. It is not intended to serve as a "backup" for apps nor to allow you to "transfer" apps from one device to another by swapping SD cards...it simply will not work in this manner nor was ever intended to.
If you factory reset your phone, the app data you moved to SD card is technically still there...but the problem is that the phone has no idea that the apps are installed in the first place.
It would be similar to if I had a Windows computer with limited space on my C: drive where windows is installed, so I add a second hard drive, which is the D: drive. Now, when installing programs I can tell them to install to directories on this new D: drive to save space on my C: drive, but if I were re-format my C: drive and/or re-install Windows, those installation directories on my D: drive would be worthless, because Windows has no idea those apps were installed there or what to do those files.
Many folks have complained that the ~9GB available on the 16GB version of the S4 is insufficient, and for some that is a valid claim...especially if you run hi-def games that can take upwards of 2GB space for a single app. This feature of allowing apps to be moved to SD was provided solely to address this issue. *IF* you are not approaching your limits in terms on internal storage on your S4, then I'd highly recommend NOT moving any apps, since performance will be better if the apps are able to run in internal storage as designed.