When we planted apple trees we ended up with three different varieties - one needed fewer cold hours than the other bearing type and the third was the pollinator. The one that needed fewer hours of cold was always our best bearer. While the other two might occasionally have a couple of apples, we never had enough to pick from them. Unfortunately, after thirty + years that is the only one left and without a pollinator it will not have fruit.

But we are in Florida so there could be significant differences in varieties for colder areas.

nice for Crab Apple Jelly and Pickled Crab Apples.

I am not talking about ornamental crab apples. One of mine has deep red skin and flesh and makes absolutely beautiful (and tasty) bright pink pickles. It might be "Prairie Fire" but I would have to dig out records to say for sure. It is very hardy and disease free.

Serviceberries (Amalanchier) are another consideration for small fruit (small tree size also). Also showy flowers in the spring. Here the bears go after them!

If you are in the right zone and want to consider nuts, think about finding a butternut (Juglans cinerea), they are a threatened native species and great eating. As with walnuts you have to be careful not to plant one where the roots get into your vegetable garden because they will kill tomatoes.

Cheers,
Agony

We're in south central PA and the largest kiwi grower (I think in the country, not sure) is only about an hour from here. To help the fruits gain size and ripen, he picks the grape-sized "berries" and sells them in bulk. That allows the tree to put its energy into fewer but stronger fruits and the small fruits are worth a fortune.