Friday should now be known as FRY-YAY for french fry fans!
According to McDonald's website, You can get FREE Medium Fries on Friday with any purchase through Mobile Order & Pay***
Customers can walk into McDonald’s locations and, by using the McDonald’s iOS app and Apple Pay, get a free order of medium french fries at check out.
A minimum purchase of $1 is required to get the free french fry deal at McDonald’s. Customers can only redeem the french fry offer once per week. The offer is only valid at participating McDonald’s locations.