Chapter 7. Integrating Multitouch and Gestures
When the iPhone was first released in 2007, the world of consumer electronics was accustomed to the resistive touchscreen, which required the use of a stylus and was limited to a single contact point. Because of these limitations, the multitouch capabilities of the original iPhone were a major selling point, and its operating system (now in its tenth iteration) was built around the idea of finger-based touch and gestures.
As the smartphone industry has evolved, all phones have moved toward this model of interaction. Capacitive touchscreens and gesture-based navigation is standard. With the exception of 3D touch in the 2015 iPhone models, the topic of multitouch hasn't changed since its inception.