- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];

    UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
    view.backgroundColor = [UIColor yellowColor];
    [self.window addSubview:view];

    void (^keyframe1)(void) = ^{
        view.frame = CGRectMake(100,100,100,100);
        view.backgroundColor = [UIColor redColor];
    };
    void (^keyframe2)(void) = ^{
        view.backgroundColor = [UIColor blackColor];
    };

    [UIView animateWithDuration:3 animations:keyframe1 completion:^(BOOL finished) {
        [UIView animateWithDuration:3 animations:keyframe2];
    }];

    return YES;
}