I always make apple crisp when I have too many apples and I need to use them before they go bad. I had frozen blueberries that I added into the mixture and while they didn't provide a ton of extra flavor, it really made the crisp look pretty! I don't have any specific measurements for this, but I can provide the ingredients I use.
Slice up enough apples to fit in whatever casserole dish you're using, add some blueberries. Sprinkle over top: about a tsp of sugar, a little vanilla, corn starch. In a separate bowl combine 3/4 of a stick of diced cold butter, white sugar, brown sugar, flour, oatmeal, cinnamon, pinch of salt. Mix everything with a fork or pastry cutter until it's in little peas. Sprinkle over top of the apple mixture and bake at 425 until bubbly and brown! That's it :) Serve plain, with vanilla ice cream, or whipped cream.