While they don’t offer any additional functionality over capacitive buttons, the software buttons that first appeared in Honeycomb and continued to Jelly Bean have become rather popular. They’re not only a modifiable novelty, but with screens as large as they are, giving up a little screen real estate for the software buttons isn’t exactly a big deal. Now, the Samsung Galaxy S III and its US variants running CM10 can have their software buttons enabled with a single mod.

The original thread was started by XDA Recognized Developer graffixnyc to bring the software buttons to the international Galaxy S III. However, XDA Forum Member NemesisRE took it a step further and developed a mod that brings the soft keys to all Galaxy S III devices.

There are five mods that users can use, all of which are flashable through custom recovery software. They are as follows:

NAV_Only: none of the hardware keys are enabled (except Volume and Power)
NAV_HomeWake: Home button wakes device but has no other function
NAV_HomeCamera: Long press Home button opens Camera and takes Pictures but has no other function
NAV_StockKeys: Functions as normal but with on Screen Navbar
NAV_Remove: Removes the mod

Not only does it work on any Samsung Galaxy S III devices, but it also may work with any device that uses the same key binding as the Galaxy S III. As NemesisRE explains:

This should work on any device with the same keybindings:
Code:
key 172 HOME
key 158 BACK
key 139 MENU
In the this files:
Code:
/system/usr/keylayout/sec_touchkey.kl
/system/usr/keylayout/gpio-keys.kl
/system/usr/keylayout/sec_keys.kl

For more info, check out the thread above or the single post for more details.