1: Before starting take a backup of all of your data and save on your system.
2: Start Samsung Kies-> Connect Your SGS 3 ,plus stay connected to your tab as well.
3: Goto Main page -> Select (basic summary) something similar to this.
4: At the base of your screen you can see : Transfer your BackUp data from Non-Samsung Device
5: You also have to select iphone 4 backup
6: Select the files you need to transfer to SGS3