Usage

adb pull /data/data/com.square_enix.android_googleplay.FFVI/filesRockDat0.sav filesRockDat0.sav.orig
adb pull /data/data/com.square_enix.android_googleplay.FFVI/filesRockDat1.sav filesRockDat1.sav.orig
./ff6 tojson -i filesRockDat0.sav.orig -o filesRockDat0.json
./ff6 tojson -i filesRockDat1.sav.orig -o filesRockDat1.json

Open up and edit filesRockDat0.json and filesRockDat1.json (or just the one with the highest "FileHeader -> Version" number) as you want, then:

./ff6 fromjson -i filesRockDat0.json -o filesRockDat0.sav
./ff6 fromjson -i filesRockDat1.json -o filesRockDat1.sav
adb push /data/data/com.square_enix.android_googleplay.FFVI/filesRockDat0.sav
adb push /data/data/com.square_enix.android_googleplay.FFVI/filesRockDat1.sav
adb shell chmod 777 /data/data/com.square_enix.android_googleplay.FFVI/filesRockDat0.sav
adb shell chmod 777 /data/data/com.square_enix.android_googleplay.FFVI/filesRockDat1.sav

Command help:

10:32 ~/code/go/src/github.com/quarnster/ff6 $ ./ff6 help
Manage Final Fantasy VI mobile save files

Usage:
	ff6 command [arguments]

Available commands:
fromjson  Convert .json save file to .sav
help      get more information about a command
tojson    Convert .sav save file to .json

Use "ff6 help [command]" for more information about a command.

10:33 ~/code/go/src/github.com/quarnster/ff6 $ ./ff6 help fromjson
ff6 fromjson

options
  -i="filesRockDat0.json": Input .json file
  -o="filesRockDat0.sav": Output .sav file
10:33 ~/code/go/src/github.com/quarnster/ff6 $ ./ff6 help tojson
ff6 tojson

options
  -i="filesRockDat0.sav": Input .sav file
  -o="filesRockDat0.json": Output .json file
10:33 ~/code/go/src/github.com/quarnster/ff6 $

There are most likely issues and incorrect mappings, pull requests please.

License

The license of the project is the 2-clause BSD license.