Soft navigation keys are desirable in post-4.0 Android device... at least for some users. Some people love 'em (and curse the likes of Samsung and HTC every time a new flagship with hardware keys comes out) and some don't. For those who don't, Good Mood Droid (whom we've featured before) has created GMD Hide Soft Keys root. It's a root-only application that gets rid of the navigation bar in all areas of the device.
We've seen this implemented in a few different ways, mostly on custom ROMs like CyanogenMod, Paranoid Android, and AOKP. We've also seen similar apps in the Play Store, like full!screen. But this is the first one we've seen that removes the navigation bar without also removing the notification tray, which tends to interrupt the user interface in frustrating ways. GMD Hide Soft Keys hides the navigation bar without having to flash a custom ROM, which is pretty great for users who just want a little bit of customization. There's a swipe-up bar integrated into the app for normal navigation, or you can install your own alternative option, like LMT PIE. There are a ton of visual customization options, and you can auto-start the app on device startup.
At the moment the app is a bit limited: the developer has only enabled downloads for Nexus devices. We can confirm that it's available to Nexus 4, Nexus 7, Nexus 10, and Galaxy Nexus users (you know, everyone who might need it). I'm also seeing it as available for some of my devices running custom AOSP-based ROMs, but again, GMD Hide Soft Keys isn't exactly useful when the feature is built into the ROM. Here's hoping it comes to more phones, especially smaller ones with on-screen navigation like the RAZR M, before too long. The app is a free download.