The toolkit does everything you could need in one easy to use application. Seriously, check out this list of functions;
Install drivers automatically
Backup/Restore a single package or all apps, user data and Internal Storage
Backup your /data/media (virtual SD Card) to your PC for a Full Safe backup of data
Perform a FULL NANDROID Backup of your system via adb and save in Custom Recovery format on your PC
Pull /data and /system folders, compress to a .tar file and save to your PC
Backup/Restore your /efs partition
Dump selected Phone Partitions, compress to a .zip file with md5 and save to your PC
Install BusyBox binary on phone
Root any public build (different options available)
Rename Stock Recovery restore files (to stop Stock Recovery flashing on reboot)
Flash CWM Recovery v4 from Team Epic
Flash Stock Recovery
Download, Extract and Flash Stock Rom via Odin (full steps)
Install a single apk or multiple apk’s to your phone
Push Files from your PC to your phone
Pull Files from your phone to your PC
Set Files Permissions on your phone
Dump selected LogCat buffers to your PC
Dump BugReport to your PC (if installed)
Help, Information Screen for various tasks
Mods Section to Modify your phone
Reboot Phone options in adb mode
ToolKit options section (Change background + text colour in ToolKit, change Model/Build, set Model Selection Screen On/Off)
The toolkit is designed for T-Mobile, AT&T and Sprint models of the device and aimed at the Snapdragon S4 processor. There is one out for the international Galaxy S III, be sure you get the right one for your device though. Anything you do to your device that results in thermal nuclear war, a dead cat or any other mischief or mayham is all on you.
To get the toolkit you need for your carrier version, hit up any of the links below. Be sure to read EVERYTHING before you start pushing buttons. mskip has provided a very detailed set of instructions that walk you through everything.
Source: XDA Portal