Apples can most definitely be boiled or cooked, and added to almost any other fruit. ...... they make great home-made applesauce on their own!
I suggest you cut or dice your apples (leaving the peel on increases vitamins, but it's a matter of your own personal taste). You can add them to the pot when the cranberries are almost entirely cooked. They shouldn't take more than 4-5 minutes to cook, since they're diced. It depends on how firm you want the apple pieces to be. Test them to be sure you don't overcook them, unless you want everything to be the texture of a puree.
Might I add, that adding about 1/4 cup of pomegranite juice gives them a delicious flavor too ..... experimenting with food opens a whole new world of scrumptiousness ..... try it ..... give your culinary talents wings!!!
