Instagram-like heartbeat animation using CABasicAnimation & CAAnimationGroup

gistfile1.txt

    NSMutableArray *animations = [NSMutableArray array];
    // Step 1
    {
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        animation.toValue = @(1.3);
        animation.duration = 0.3;
        animation.fillMode = kCAFillModeForwards;
        [animations addObject:animation];
    }
    {
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
        animation.toValue = @(1.0);
        animation.duration = 0.3;
        animation.fillMode = kCAFillModeForwards;
        [animations addObject:animation];
    }
    // Step 2
    {
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        animation.toValue = @(1);
        animation.beginTime = 0.3;
        animation.duration = 0.1;
        animation.fillMode = kCAFillModeForwards;
        [animations addObject:animation];
    }
    // Step 3
    {
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
        animation.toValue = @(1.3);
        animation.beginTime = 0.4;
        animation.duration = 0.3;
        animation.fillMode = kCAFillModeForwards;
        [animations addObject:animation];
    }
    {
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
        animation.toValue = @(0);
        animation.beginTime = 0.4;
        animation.duration = 0.3;
        animation.fillMode = kCAFillModeForwards;
        [animations addObject:animation];
    }
    
    CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
    animationGroup.animations = animations;
    animationGroup.duration = 0.7;
    animationGroup.fillMode = kCAFillModeForwards;
    animationGroup.removedOnCompletion = YES;
    
    [self.heartPopup.layer addAnimation:animationGroup forKey:nil];