“(It) is one of the best apps to use when searching for cheap flights,” says Alex ... business and first-class flights as well as mistake fares from all U.S. airports. It costs $199 per ...

Frontier is also offering a free checked bag for flights departing between May 28 and Aug. 18 with promo code FREEBAG. Frontier will add first class seating to every flight starting in late 2025.