Apples are one of the least expensive and most popular fruits. It seems perfectly adapted for many parts of the country, making apples and apple juice ubiquitious in US cuisine. What is more (Anglo) American, after all, than apple pie?
At the right time of year, usually starting in early fall through mid-winter, apples tend to be cheap, and these days are available in incredible varieties, not just the red and golden delicious that dominated the stores when I was a kid. Different varieties are good for different things and different tastes. I personally don't care for the red and golden delicious apples as eating-from-hand apples myself. They aren't as crisp as granny smiths and they're sweet rather than tart. But that's why the wide varieties are so much fun, there's at least one for almost every taste.
Apples can be eaten in so many ways too. The simplest, of course, is just to wash and eat it as is. I used to feed my children regular applesauce from a jar (but I didn't feed solid foods until almost 6 months so they went directly to ordinary things like applesauce, yogurt, and cream of wheat. Jarred applesauce is probably the cheapest "canned" fruit or vegetable. My mother occasionally made hot homemade applesauce which was very good, but it was a lot of work, and my little sister (about 5 at the time) once flipped a plate of it into her face, and she stopped making it after that.
Apples can be turned into a quick, healthy dessert too. Grease a small baking pan, slice up an apple or two, spread out the slices, sprinkle with cinnamon sugar, and bake at 375F until soft. Or layer them more thickly and cover with a brown sugar crumb topping and bake for an apple brown betty.
Apples can make it into main courses too. Waldorf salad relies heavily on apple. And fried apple slices used to be a part of many farm breakfasts. Applesauce can be substituted for some of the fat in some baking as well, though I haven't tried it myself. But most people don't realize that the versatile apple can be used in stews and soups like potato. I have had a "winter stew" with potato, turnip, parsnip, and apple that was incredibly delicious, and no one guessed that one of the vegetables was apple (he did use a particular type of apple, and I don't recall which, but avoid the really sweet ones, I think). Now, generally, apples cost more than potatoes, so you wouldn't save money by substituting them, but if you buy a big bag of apples, and you need to use some of them up, this might be a way to do it. I've also had a curry that included apple. It would take some research to find one, but it's just one example of the possibilities.