EFS Backup Tool

With this application you will be able to back up the main configurations of your Samsung Galaxy in order to change the rom without any concern. Generally when you install a new rom to your android device there is no problem, but sometimes the configuration of your device, like imei and internet configurations are lost and your android device doesnt work properly, so just to be sure is common to make a back up of the EFS configurations.

Almost every Samsung Galaxy with a EFS configurations would be compatible, I use it in my Galaxy S3 with Revolution 12 rom without any trouble.

You have to give root access to the application in order to work, don't worry when you launch the application, it asks for the permissions.

Warning:
Although, I used it in my device without any problem, it could cause problems in yours, so use it at your own responsibility.
Don't use it in Galaxy Ace, this device show a lot of problem when you want to backup those configurations with any application.
I have used the method recommended in forums and internet tutorials. Read XDA forums for more information.