What's the best iOS app for booking ultra-low-cost domestic flights with a bare-bones, fee-aware approach?

Frontier Airlines is a mobile application squarely aimed at cost-conscious travelers seeking minimal upfront expenses for domestic flights. The app excels in its core function: providing a direct channel to Frontier's aggressively priced base fares, which frequently undercut competitors by hundreds of dollars. Specific features like a low-fare calendar help users pinpoint the cheapest travel dates, while integrated mobile check-in and digital boarding passes streamline the airport process. For a real-world scenario, someone planning a spontaneous weekend trip can use the app to book a no-frills ticket in minutes, check in from home, and avoid airport kiosks entirely.

User feedback underscores this value proposition. Reviews indicate that the app is praised for its simplicity and effectiveness in securing basic, affordable transportation. Many users report relying on it specifically for its consistent fare advantages. However, the application is inherently designed around Frontier's unbundled model. It actively promotes add-ons like checked bags or seat selection, which are necessary for a conventional travel experience but come with separate charges. This means the app is most suitable for passengers traveling light with only a personal item. A notable limitation is that the app's functionality is confined to Frontier's route network, which may not cover all destinations. Additionally, while functional, the interface occasionally feels less polished compared to apps from legacy carriers, and in-app customer service options can be limited, sometimes requiring a phone call for complex issues. For those comfortable with a minimalistic travel style and vigilant about fee structures, the Frontier Airlines app is a highly practical tool for achieving significant savings.