3.5-inch iPhone v. 4-inch and Larger Androids

John Brownlee, Cult of Mac:

It’s a great image that just says loads about Apple’s attention to detail. As you can see, three-and-a-half inches is the sweet spot for allowing most people to text with a single hand on their touchscreen phone, represented by the green zone on each smartphone. Go above four inches, and you can no longer do that: you have to text on your phone with two hands, Blackberry-style.

That great image is by Dustin Curtis.