Keyboards and Input Views
In iOS 8 and later, you can create a custom keyboard extension that people can use instead of the system-provided keyboard in most places. To learn more about the guidelines that govern app extensions including keyboards, see App Extensions; to learn how to develop a custom keyboard extension, see Custom Keyboard.
If appropriate, you can also design a custom input view to replace the system-provided onscreen keyboard within your app. For example, Numbers provides several input views that are designed to make it easy and efficient to enter amounts, dates, and other values.
If you provide a custom input view, be sure its function is obvious to people.
You can also provide a custom input accessory view, which is a separate view that appears above the keyboard (or your custom input view). For example, in some contexts, Numbers displays an input accessory view that helps users perform standard or custom calculations on spreadsheet values.
Use the standard keyboard click sound to provide audible feedback when people tap the custom controls in your input view. To learn how to enable this sound in your code, see the documentation for
playInputClick in UIDevice Class Reference.