3.9. Pointed Design

So far, this chapter has emphasized the physical more than the visual, pushing the ergonomic angle of app design. As always, though, form follows function, and all this talk of tap targets and thumb-friendly layouts influences more than just button sizes. When you plan the placement of your app's touch controls based on comfort and ease of use, other aspects of your design naturally fall into place. The best iPhone apps also share a common visual hierarchy broadly following these tap-friendly guidelines:

• Place important info at the top and sink controls to the bottom.

• Design to a 44-pixel rhythm.

• Where appropriate, create at-a-glance displays that avoid scrolling.

• Whittle onscreen elements to the bare minimum.

• Push advanced tools and controls to the background.