But how these elements respond is just as important as how they look. For example I hope the six main buttons give a nice depressed feel when touched, and not a crappy blue highlight.
Two things I feel are problems -
1) The settings icon at the top-right is too much towards being part of the surrounding image and not enough of a touch-target.
2) Both bump images suggest that you just hold the phones next to each other and they wirelessly communicate. There's no feeling of the movement or motion needed to start that process.
Bump iOS developer here. It's hard to get a feeling of the redesign of an app just from screen shots (i.e. you can't tell what the depressed state is from a screen shot). You also can't tell that in the real app the hands are animated, showing the bumping motion in all its non-linear core animation glory.
The touch "area" on the settings button is actually decent sized, but it is not emphasized, as it is not an area that most users need to go to. We want it to be visible, and easily discoverable if that's what you are looking for, but not a big attractive button. We've found that users like to press anything that looks pressable. The fewer distracting things we put in front of the, the more likely they'll get to the good stuff sooner.
One suggestion; more space below and above BUMP logo.
