iOS Messages app with sticky input field being dismissed interactively

When designing user interface for an app with an input field as primary focus of interaction (to accept and display text input), it’s a common pattern for the input field to stick (stay on the screen persistently). The input field attaches to the top of the keyboard and moves along with it.

Apple’s Messages is a great example for an app displaying the aforementioned UI pattern. Since iOS 7, the app also allows users to dismiss the keyboard interactively while dragging down upon the scrollable view.

This pattern can be seen in most if not all, chat apps. Few have managed to execute it as well as Apple’s Messages app, notable examples being Facebook Messenger and WhatsApp.