The other day, I found it necessary to trim my apple tree due to the fact that it was looking like it was being blown over in a hurricane, despite the lack of wind. After pruning, upwards of three hundred half-size granny smith apples came down with the branches. Now, they’re not exactly ripe, but I hate to see anything go to waste. Is there any recipe or food out there that requires premature apples to make? What can I do with them?
At this stage they will be quite sour and packed with pectin; any recipe that calls for crabapples would work well.
Years ago, my father had the same dilemma. He decided to pile the apples around the base of a dying pine tree in our back yard. “The only pineapple tree in the area” he’d joke. Within a year, the pine tree thrived and grew to be rather mighty, so it turned out to work well as plant food, at least.
Call the local zoo, if there is one, and ask if they can use them for animal feed. Or perhaps a local stable.
Interesting idea. What does crabapple juice/sauce taste like?
As someone else already suggested, compost them so your future Granny Smiths might turn out better.
Or, make them into cider. (Don’t ask me how, though. I have no clue.)
Cider, or apple pies – but increment the amount of sugar called for in the pies, and add some sugar or sweet syrup to the cider.
Instructions for making cider (This deals with how to make hard cider, but the initial phase gives the right instructions for how to make the non-alcoholic good-for-the-kiddies kind.)
Stem cell research? 
Well, there are plenty of stems, true 
Crabapple jelly is very nice; either as a breakfast spread or as an accompaniment to roast meats. Juice might be very sour, but even that could prove useful; in olden tymes, they used to make something called verjuice out of sour apples; it would be used for the same sorts of things as we might use lemon juice or vinegar.