Skip the line with the Shack App, Shake Shack’s mobile ordering app that lets you save time by ordering ahead for pick-up and delivery! Simply login, select Buckhead location, pick your food, choose a pickup time and your meal will be cooked-to-order and timed to arrival. Available on iOS and Android. Residents at The Charles can enjoy 10% off their Shack App order with promo code CHARLES22. Promo code is also available for The Charles residents card holders that will be dining in-house. Simply mention the promo code: CHARLES22.