Time Out Facility in iPhone SDK

Use this code when you want to put requirement of Time Out with any view controller .. here in which view controller you want to put this facility then use this simple code and add in your file..

@interface MainViewController : UIViewController
{
    NSTimer *idleTimer;
}
@end

#define kMaxIdleTimeSeconds 60.0

@implementation MainViewController

#pragma mark -
#pragma mark Handling idle timeout

- (void)resetIdleTimer {
    if (!idleTimer) {
        idleTimer = [[NSTimer scheduledTimerWithTimeInterval:kMaxIdleTimeSeconds
                                                      target:self
                                                    selector:@selector(idleTimerExceeded)
                                                    userInfo:nil
                                                     repeats:NO] retain];
    }
    else {
        if (fabs([idleTimer.fireDate timeIntervalSinceNow]) < kMaxIdleTimeSeconds-1.0) {
            [idleTimer setFireDate:[NSDate dateWithTimeIntervalSinceNow:kMaxIdleTimeSeconds]];
        }
    }
}

- (void)idleTimerExceeded {
    [idleTimer release]; idleTimer = nil;
    [self startScreenSaverOrSomethingInteresting];
    [self resetIdleTimer];
}

- (UIResponder *)nextResponder {
    [self resetIdleTimer];
    return [super nextResponder];
}

- (void)viewDidLoad {
    [super viewDidLoad];
    [self resetIdleTimer];
}

@end

get another example for this facility from this answer of stack-overflow iphone-detecting-user-inactivity-idle-time-since-last-screen-touch