Jeju Air is a free mobile application that provides travelers with an easy and convenient way to book and manage their air tickets. The app is optimized for mobile users, offering a faster and simpler booking and boarding service. With Jeju Air, you can access 24-hour booking and boarding services from anywhere in the world.

The app offers a range of features that make air travel more comfortable and convenient. These include the ability to manage air ticket bookings, purchase seats, baggage services, and in-flight meals in advance, and receive real-time booking and boarding information notifications through 'App Push'. You can also inquire about flight schedules, departure/arrival times, and issue domestic/international line mobile boarding passes.

Jeju Air also offers membership benefits such as Refresh Points, translation services in five languages, and simplified SNS login to Google+, Facebook, Kakao Talk, and more. In addition, you can get air ticket discount promotion codes, information on Travel Lounge travel packages, and information on partnership discounts of hotels, rental cars, etc. The app also allows you to reserve in-flight duty-free goods.

Overall, Jeju Air is a must-have app for any traveler looking for a simpler, more convenient way to book and manage their air tickets.