I've been making great, easy fruit pies using Trader Joe's 100% sour cherry juice. It is so flavorful and sweet that I barely need to add any sugar. I don't use a recipe but it's something like this:
Crush 1 1/2 columns of sandwich cookies in food processor till crumbed. Stir in 2-3 tblsp melted butter. Press into pie pan or 9x9 square pan.
Stir about a cup or so sour cherry juice (depending on how much goo you want), a couple spoonfuls of corn starch, and a spoonful of sugar together on the stove until it thickens (right after it boils). Put 1 1/2 lbs of fresh pitted cherries (regular or sour cherries) OR 1-2 pints blueberries in the pie crust. Pour the goo over the fruit. Bake at 375 for 45 minutes.