Mash blueberries in a bowl. Add sugar, lemon juice, salt and gelatin or tapioca. Stir until well mixed.
With a pizza cutter, cut off sides of the pie crusts and cut into 12 rectangles.
Spoon about 2 tbsp of the blueberry mixture onto 6 of the pie crust rectangles.Top each with another rectangle of pie crust. Then, use a fork to press the edges together all the way around to seal.
Using the fork, poke three rows of holes in the top pie crust at a diagonal.
Using a toaster oven or conventional oven, bake on a lined baking sheet for about 12-15 minutes at 350˚ or until golden brown.