This has been my app experience the last 3 times I've used it. 1-Log in at kiosk 2-scan coupon 3-"oops something went wrong" 4-attempt to use different coupon 5-get a message that I've used a coupon recently and need to wait 15 minutes to try again. This is across multiple phones. Tldr McDonald's is okay but the app isn't worth your time.