Question

How can I quit iPhone4 app? When I use exit(0) the app goes in the background. I want to quit the app instead of sending it to the background.

Answer 1

iPhone apps shouldn’t have a quit button. The user quits by pressing the main button.

From Apple’s docs: (http://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/MobileHIG/MobileHIG.pdf)

People quit an iPhone application by opening a different application. In particular, note that people don’t tap an application close button or choose Quit from a menu. In iOS 4.0 and later, and on certain devices, the quitting application moves to a suspended state in the background. All iPhone applications should:

• Be prepared to quit at any time. Therefore, save user data as soon as possible and as often as reasonable.
• Save the current state when stopping, at the finest level of detail possible. For example, if your application
  displays scrolling data, save the current scroll position.

iPhone applications should never quit programmatically because doing so looks like a crash to the user. There may be times, however, when external circumstances prevent your application from functioning as intended. The best way to handle this is to display an attractive screen that describes the problem and suggests how users can correct it. This helps users in two ways:

• It provides feedback that reassures users that there’s nothing wrong with your application
• It puts users in control, letting them decide whether they want to take corrective action and continue
  using your application or press the Home button and open a different application