1 piece of fruit spaced out by the width of your hand to 6". just a general rule for thinning, so don't let two apples grow closer together than that. in terms of total your should have, it depends on the year, the conditions, etc. The trees look nice, so i would say you should end up with a nice harvest (even after thinning). Do you know the varieties?

No, I don't know the varieties. I wish I did.

Thanks for the thinning info. That is helpful.

The reason i was asking about the varieties, is that some just don't get big. So thinning may not do much for size. Good Luck!

How many depends on how you pruned, mulched, fertilized, thinned the fruit, etc, your spraying regime. Each year may be much different.

If you could post close up pictures of the blossoms or of the fruit, later on, people might be able to tell you if you have a crab or not. As Jason said, they may just be a small variety.

I only found 1 blossom left, so here is a pic. Also a few pics of the small fruit.
Can anyone tell this early if the trees are crabapples or not?

That flower, to me at least looks more like a regular apple, not crab apple (that said there are thousands upon thousands of varieties of apples out there).