Combine gelatin, cranberry and grape juice in microwavable bowl. Set aside for 1 minute, then microwave for 30 seconds. Take out, stir, and set aside.
Gelatin should be dissolved. If not, microwave for another 10 or 15 seconds, stir, and set aside.
Wash fruit; slice half of the strawberries into a size you want to top the pie with. Dice the other half.
Combine diced strawberries, gelatin, half the blueberries and yogurt in a blender. Blend until smooth and creamy and all is incorporated.
Pour into crust and chill for about 5 hours until set. Top with grated lemon zest, then the whipped topping (optional, but so yummy) and decorate the top with the rest of the strawberries and blueberries. :0)