Since I purchased my Nexus 4, creative use of the extra screen real estate occupied by the soft button strip has been important to me.
I have been extending my screen to cover this strip when in games or certain apps to show more content, by using the very easy-to-use feature available in CyanogenMod 10.1.
1. Under “Settings > System > Power Menu,” check “Expanded Desktop.”
2. Click and hold the power button to access the power menu.
3. Select “Expanded Desktop” from the power menu. This is a toggle item, which means that you may repeat steps 2 and 3 to make the soft buttons appear again, contraction the desktop.
Note: you must have CyanogenMod 10.1 Custom ROM, not what the device ships with. You may start at http://www.CyanogenMod.org if interested.