It actually looks sweet!

Two things that I would probably try here (sorry, I don't know the technical designer lingo, but I'll speak from a consumer point of view):

1. Increase the space between the lines of a navigation menu items in your second screenshot. I find that you need a bit more space in order to hit the right menu item fast and with confidence.

2. In order to increase the screen real estate (after all not all smartphone screens are made equal), remove the footer navigation and instead, add a button or a solid panel at the top of the page that would say something like "JUMP TO" which will open a drop down menu with those main navigation choices. It will also allow you to grow the number of menu options down the road.