Just above the tab-bar buttons at the bottom of the screen, the app offers a narrow utility bar with a button to refresh content and the standard "i" settings button. Locations near the tab bar always make for troublesome tap targets, a problem compounded by the need to save space and make the buttons small.
Rusty: We knew that if we were going to fit these controls on the screen, they were going to have to remain small and unobtrusive. They needed to hold the correct hierarchical weight and if they were going to have their own bar in the interface, it needed to take up as little vertical space as possible. The main problem presented itself early on: because of the small size of the info and refresh status bar and its proximity to the tab bar, we found that it was much too easy to inadvertently switch sections in the application when attempting to tap "i" or refresh. We had the idea that, instead of making the buttons themselves larger, we could make their invisible tap area larger instead. They would still take up the same amount of space, but they would be easier to hit.
Unfortunately, Apple had the same idea. When we tried to add a larger tap area to our buttons, we discovered that the tap area for buttons in the standard tab bar extends several pixels above the tab bar, right into our info and refresh bar. That not only blocked our attempt to use those pixels for our info and refresh buttons, but it actually made our problem worse than we originally knew. Since Apple doesn't give developers control to adjust the tap area of the standard tab bar, we had to build our own custom tab bar control so that we could control the tap area and make this idea work.