SkeletonView
A way to show users that something is happening and prepare them
...If numberOfLines is set to zero, it will calculate how many lines needed to populate the whole skeleton and it will be drawn. Instead, if you set it to one, two or any number greater than zero, it will only draw this number of lines. The skeletons have a default appearance. So, when you don't specify the color, gradient or multilines properties, SkeletonView uses the default values.