I say it's apple scab, a fungal problem. Use fungicide like Immunox or Captan. I like Immunox because it is very effective on Apple Cedar Rust, another very common apple tree issue.

Oh, thanks so much. I believe I have immunox - hope it is non toxic. I did see on another post that worm castings sprayed on the tree is anti fungal.

I'll see if I have it.

Thanks Carol

Carol if that picture was not taken during growing season the look of the leaf doesn't matter. When the leaves are about to fall off they get all sorts of funny looks because they are starting to decay already. I don't think its scab, the spots are green so they are the healthy bit and scab is the opposite.