Android devices are probably user favorite because it has a lot of interesting features to play with. Like customizing the skin, sense, overclocking to get the most of your Android device and even you can flash the whole ROM and counting. Android also got some hidden features as well, which obviously can’t be hidden for so long from our skilled developers. One such feature is to access various hidden apps using custom dialer codes on your Samsung Galaxy S III. For instance, *#*#197328640#*#* gives you access to the Service Menu.
XDA Recognized developer E:V:A has not only provided with some of the secret codes to access hidden apps but also showed one of the ways where you can find the secret codes by yourself. To get those codes you need to install these applications first:
Get jd–gui (Often crashes) Get jad (doesn’t crash, but is cmdline based) Get sgs2toext4 (and here) Get Disk Internals Linux Reader Get a disk image with deodexed Apps
And then after that you can find codes by yourself and even the developer shows some ways to find new little hacks. It sure is an interesting thing and if you are excited and curious enough to find some more, head over to the original thread.
Source: XDA Developers