Burger King is offering a Kids Meal, Whopper, or Impossible Croissanwich for FREE with any purchase made through the BK mobile app at participating locations for a limited time. This offer is valid for takeout, drive-thru, and delivery orders. The Whopper offer requires you to use Apple Pay as your form of payment. Delivery is Free with orders of $10 or more. Plus, it can be redeemed once per day until the stated expiry date on each offer.