iOS built-in functions

[macbookbie]

Hm... I have always curious about the built-in features that already have integrated for developers within xcode. Where do I find those features, for example, the built-in backgroundcolor that allows you to change the color of the view background, what about other built-in features that I can use to interact with iMessages, or even the volumn and sleep buttons on the phone? I hope I am making sense.