From XDA site:
" If you have 16GB internal storage on Galaxy S3, you can install this witih a 64GB microSD card and swap the storage and get 64GB on your app storage instead of 16GB."
[MOD]App2ExtSD2 [Works for all U.S. Galaxy S3!] - xda-developers
" If you have 16GB internal storage on Galaxy S3, you can install this witih a 64GB microSD card and swap the storage and get 64GB on your app storage instead of 16GB."
[MOD]App2ExtSD2 [Works for all U.S. Galaxy S3!] - xda-developers