A discussion about flat design and responsive design

I love the iPhone 5. The extra 640×76 pixels for content is very useful. But, I’ve had a lot of trouble accessing the most used button of all: the back button. As a rule in user experience, when a function is this frequently used, it should be made easily accessible. 49% of mobile users use their phone with one hand, this means that almost 1 out of 2 users use the back button several times a day. That’s billions of awkward taps daily. It’s even worse with bigger phones because you would almost certainly have to use your 2 hands to reach the back button. I guess that could be one reason why Android has their hardware back button on the bottom left, but still, it’s not that great since the back button can differ from the “up” button.