iOS 8 and iOS 9
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:UIApplicationOpenSettingsURLString]];
There is no way to do this.
Because till now (11th Jan 2013) there is no url scheme available for settings app.
iOS 6
You can't do this on iOS 6.
iOS 5 and below (< iOS 5.1)
[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"prefs:root=General"]];
Please refer this answer for more info Call the official *Settings* app from my app on iPhone
