Drain pineapple, reserving juice; set pineapple aside. Add enough water to juice to measure 1 cup. Pour into a small saucepan; bring to a boil. Carefully pour into a large bowl; stir in gelatin until dissolved. Add ginger ale. Refrigerate until syrupy, about 45 minutes.
Combine the cranberry sauce, apple, celery and reserved pineapple; fold into gelatin mixture. Transfer to a 9-in. square dish. Refrigerate until firm.
In a small bowl, beat cream cheese and sugar until fluffy. Prepare whipped topping mix according to package directions; fork into cream cheese mixture. Spread over gelatin. Sprinkle with pecans.