I can’t find a carb count for them, but beings that they are plain cranberries in dried form, and they have zero sweetness to them, I assume they are just fine to use.
I use them in stews and soups, casseroles and gravies to add tang. A little goes a long way, and they work for anything that would be good with lemon or vinegar also, and a lot of things that would not. They add a great amount of tanginess to everything meat.
I cook by ears, eyes and taste, so I don’t have any recipes to post, but experiment with adding some to anything you like a little tangy - You can start by just dropping one in , letting it plump up a bit, and taste a spoonful of the liquid around them. Then you can adjust according to taste.