I recently fought with a android nexus 4 that had water damage to the digitizer. So touches would not register for the bottom part of the screen a (a cm or more).
I tried many things but in the end I ended up flashing to android 4.4, rooting it and then using xposed framework to increase the size of the navigation bar using it's dimens module. xposed doesn't work yet on lolipop / android 5.0 but maybe it will soon. Also, with xposed - you need to take a few steps to make sure it's installed and the dimens module is checked on.
During the process I found that the screen rotation app helped alot. Specifically set orientation -I forget the setting, but getting that installed is key. Also handy soft keys helped a lot.
So now my navigation bar is so big that it blocks out the dead part of the touch screen.. but I loose screen real esatate though.. also the back button seems to trigger search for some reason.. not sure why.
