Force iphone app to restart programmatically?

First of all, although it is possible to force kill your app, this is not allowed by Apple and will rejected. Even if it wasn't rejected, there is no way to restart your app once it's killed. You just need to find some way to reset your app through your code, as Jason Coco said. It might be more work, but it's worth it to not get rejected by Apple.

try this, it works for me.

-(void)restart
{
    MyAppDelegate *appDelegate = (MyAppDelegate *)([UIApplication sharedApplication].delegate);
    [appDelegate.navigationController popToRootViewControllerAnimated:NO];
    UIViewController *topViewController = appDelegate.navigationController.topViewController;
    Class class = [topViewController class];
    NSString *nibName = topViewController.nibName;
    UIViewController *rootViewcontroller = (UIViewController *)([[class alloc] initWithNibName:nibName bundle:nil]);
    [appDelegate.navigationController.view removeFromSuperview];
    appDelegate.navigationController.viewControllers = [NSArray arrayWithObject:rootViewcontroller];
    [appDelegate.window addSubview:appDelegate.navigationController.view];
    [appDelegate.window makeKeyAndVisible];
}