(Edit - Definitely YMMV, Offer is surely available in Chicago area. Please check your app to know whether you got this free sandwich coupon)
Wendy's is offering any size of Fries at $1.
Combine your $1 fries with this Wendy's App Coupon - Free Spicy Chicken Sandwich with any purchase. (YMMV)
If you have other coupons in your app, it can always be stacked in one purchase (from my experience at my local Wendy's order counter/ Drive-in).