Oh..don't bin it. Although that is unsightly and can spread into fruit, unfortunately it is very common and any apple can get it at anytime in their life...some varieties are more prone to it than others. There is one very easy remedy for it that will keep it in check if it doesn't clear it...garlic spray. Give few sprays during growing season starting from when the buds are just opening.
There is few different fungal sources that cause those brown spots..some are more of trouble than others and if you are lucky..it is just something environmental that will clear when the tree is happily growing in its new permanent position.
