In order to use your McDonalds coupons you will first have to install the McDonalds app into your smartphone, tablet or any device that is compatible with the app. Once you select an offer that you found at dealcatcher.com, you will then be taken to your McDonalds app and it will tell you if that offer is available in your location. If it is available, simply select the offer(s) you would like to use, click use at restaurant and you will be given a QR code as well as a numbered code (you may use either one) that you will present before paying your order.