Two handsets that are very powerful are the Samsung Galaxy S3 and the Samsung Galaxy S4. There are many owners of the devices even though there are newer handsets out now. If you have a locked handset there is good news as you can unlock it thanks to a leaked code.
The leaked unlock code means that you can now unlock your Samsung Galaxy S4 and S3 free of charge from your own home.
To begin the unlock process you should put a new SIM card into your handset and then turn the device back on. You should then get your dial pad open and then type in *#197328640#. Once you have done this you should copy the following below.
 UMTS >  Debug Screen >  Phone Control >  Network Lock > Options  Perso SHA256 OFF.
You now need to wait for 30 seconds and you can then go to the main menu and you will now see Network Lock. You then choose  NW Lock NV Data INITIALLIZ and if all goes to plan you will now have a device that is unlocked.
The unlock code for the Samsung Galaxy S4 and S3 is also said to work on other handsets from Samsung.