With the introduction of Honeycomb, Google removed the need for physical and capacitive navigation buttons, replacing them with nice onscreen buttons that accomplish the same purpose. Galaxy Nexus aside, it would seem as if OEMs failed to receive the memo, as they continue to ship handsets such as the International Galaxy S III that feature physical and/or capacitive buttons.
XDA Recognized Developer graffixnyc is not a big fan of TouchWiz UI or physical buttons, so when CM10 Preview was released for the i9300, he jumped on it. After using it for awhile, he craved the onscreen buttons instead of the physical, capacitive ones. In order to assuage his need for the onscreen buttons, he decided to create his own mod to do just that. Says graffixnyc:
I really liked the on screen nav buttons on the GNEX. At the time I had the Galaxy S II and enabled them with AOKP but as much as I liked them I hated losing the screen real estate on the 4.3 inch screen. When I got the GS3 I felt the screen was big enough to give up a little screen [real estate] for the nav buttons. I also did it because when I play games or hold my phone in landscape I would accidently hit the capacitive buttons so this mod also eliminated that for me.
In putting together the mod, he used XDA Senior Member evilisto‘s guide for accomplishing this on ICS. He then began pouring through the Jelly Bean framework-res.apk to adapt the process to Android 4.1.1. He was successful and has now shared his work. The mod has the following variants: