Not sure why so many parents are at a loss for healthy snacks to give their kids for school, or when they return home in the afternoon (or for themselves for that matter). There is no need for a snack to come in a little packet. There is no need for a snack to be something ready made from the supermarket. There is no need for a snack to be full of sugar, salt and a whole bunch of unpronounceable ingredients. A snack can very well be something so easy and natural even your child can put it together in minutes and consider herself a mini chef. Case in point - apple sauce. I cook it in big batches and freeze it in glass jars. My daughter devours it. It is one of the easiest things to make and one of her favorite snacks. I also put it in her lunchbox in a little plastic container, and should you have leftovers (not in my house) you can serve it over hot cereal, and it is delicious on a piece of hot buttered toast. Teach your kids to make it: simply cut up lots of apples, a whole big pot full so it's worth your while, remove cores but leave the skin on (!), add lots and lots of cinnamon and a few tablespoons of water (just so the apples don't burn until they begin to sweat), put on low heat, simmer until soft, purée in a food processor - yum.
Case in point - vegetables with dip. I recently got a big bag full of snap peas from our food coop. They were sweet and crunchy, great to munch on like that, and they easily last several weeks in the fridge. We ate them with a dip made with Greek yogurt, paprika, salt, and caraway seeds, and also with homemade hummus (other case in point).
Snacks don't get much easier and healthier than that. Also look back on an earlier snack related post - there's no food - with more ideas.