Free Coca-Cola Slurpee - Get a medium Coca-Cola Slurpee at 7-Eleven for FREE! Simply download the 7-Eleven application for iOS or Android and register. This free offer can be found in the "Savings" section. Make sure you don't click the "Redeem" button until you're ready to use it, because it's only good for 15 minutes when you do. This offer is valid 8/30-9/01 only, while supplies last