The black bar on top should be narrower so that the red buttons in the bar are more noticeable. The red buttons should be left aligned. I initially had trouble locating the Home button. It nay not hurt to also include Home with the "index" buttons.

The "index" buttons along the right edge should be on the left edge instead (unless this for Hebrew or Arabic consumption :) ).

The buttons on the bottom I find redundant and only adding to the "busyness".

I like the color shift in the "self-referencing" index button.

YMMV.