We have a crab apple tree in our yard near the driveway. Every year it is loaded down with crab apples.
I do not know if it grew wild or if it was planted by the previous owners. It was here when we bought the house. It is beautiful tree in the spring when in bloom. I’ve never really known anyone to do anything with crab apples. I’ve seen them around, but always just assumed they were wild and had no use other than a home remedy for constipation.