How to make stacking effect (like notifications screen) using UICollectionView?

Question

I want to make cells stack like this.

What I'm ended up doing is reverse zPotision

cell.layer.zPosition = -indexPath.row;

and decrease the distance between each cell

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
     return -self.cellHeight + 15;
}

and make cells smaller base on the order

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
     CGFloat size = (indexPath.row * [[UIScreen mainScreen] bounds].size.width) / 20;
     return CGSizeMake([[UIScreen mainScreen] bounds].size.width - size, self.cellHeight);
}

but this seems not going to work because

1. For some reason, I can't tap on the first cell's button, seems like something is blocking it.
2. If it's possible (just an extra question, my main problem is the first one), I want to make it rotate like this but I'm not sure where can I add those codes.

and the fold/unfold animation on the notification screen is smoother too.

Is there any better way to do this? I feel like what I'm doing is not the correct way.