I just posted similar question in the disease identification thread. Only two apples from the last year graft look very russeted and cracked, all the other fruits from many other varieties seem to be normal. I worried that it might be a disease or virus issue.
These fruitlets looked similar to yours when they were younger.
So I read a little and found out that russeting and cracking is a common problem in some varieties of apples. Mine is Cox’s Orange. It is caused by the different stress factors, such as sulfuric sprays, humid weather, certain fungus, microelement deficiency. But the main factor is genetics and the thickness of the skin and the wax layer on the apple. At least it is a disorder and not a contagious disease. 