[@"codeHelper"]; is a great app for iOS and Mac developers. This app gives you examples of code elements as well as the actual code used in the examples. [@"codeHelper"]; also provides links to videos for each code element. The following code elements covered in this app are as follows (though we hope to keep adding more in the near future):
UILabel
UIButton
UISegmentControl
UITextField
UISlider
UISwitch
UIImageView
UITextView
UIWebView
UIScrollView