1. Combine crushed pineapple and unflavored gelatin in a saucepan. Allow gelatin to soften 5 minutes.
2. Bring to a boil, stirring to dissolve gelatin. Remove from heat. Stir in cold water.
3. Fold in grated apple. Chill until firm.
4. Top with 2 tablespoons non-fat whipped topping to serve.

Note: Gel will turn the color of the apple peel unless folded after the mixture begins to set, or peel the apple before grating.