Clone of Mc Donalds app promo screen. Present this screen at your nearest McDees and only pay 90c (ZAR) for a burger
Their current app allows you on first time registration to redeem a voucher for a Cajun Chicken Burger for only 90c. I was amazed that the only verification was a 5 min countdown timer (From when you initially press redeem) and the date which is displayed in the golden circle.
Since thats all they check, one could simply open this page in your phones browser and present this to them as many times as you like.
This is very basic, feel free to contribute.