Pour the canned fruit, with its juice, into a serving bowl. Core the apple but do not peel it. Cut the apple into bite-size pieces and add the pieces to the bowl. Stir to coat the apples with the juice.
Slice the banana and add it to the bowl. Add the grapes, cutting them in half, if desired. Set the fruit aside, without stirring, until just before serving.
When you are ready to serve the salad, stir the fruit and serve it in small bowls. Spoon a little of the dressing on top of each bowl and pass the rest at the table.
NOTE: If you are waiting a while to serve the salad, don't peel, slice, or add the banana until right before serving. The banana can hold in the salad for only about 10 minutes before turning brown and mushy.
Strawberry Yogurt Dressing: Pour the yogurt into a small mixing bowl. Add the orange zest (if using) and the orange juice. Stir until well combined. Spoon over fruit salad or refrigerate, covered, until ready to serve, up to 24 hours.