Public:Field Test Mode

Manufacturer	Mobile Phone	Code	Firmware	Comment
Apple	iPhone	*3001#12345#*	iPhone OS 4.0
Samsung	Galaxy S3	*#197328640#	Android 4.1.2	Choose in MAIN MENU [1] DEBUG SCREEN and then [1] BASIC INFORMATION
HTC Android devices		*#*#4636#*#*
Some Samsung, Motorola and Sony Ericsson Android devices		*#*#4636#*#*
ZTE Android devices		*983*3640#

Here you can find another great site with field test codes:

• phoneftd.blogspot.ca
  
• fieldtestmodes.pdf