Steven Hoober revisits some research and finds some interesting new things in Design for Fingers and Thumbs Instead of Touch. One of the key findings here is that it’s more difficult for users to accurately touch targets on the edge of the screen than those closer to the center of the screen.
This doesn’t mean that designers should abandon the screen edge when placing navigation. Rather, touch targets near the edge should be larger and have ample space around them to avoid interference. Hoober offers more recommendations in his article that are applicable to all designs for touch environments be they native or browser based.
Diagram from UX Matters