더데이 is a free Android app developed by HSA apps. It falls under the category of Business & Productivity. The app is designed to help users keep track of their upcoming exams, including the 2021 and 2022 수능 (Korean College Scholastic Ability Test), various 공무원 (government job) exams, and other certification exams such as 토익 (TOEIC).

The app provides a countdown feature on the home screen and a widget, allowing users to easily see how many days are left until their exams. With 더데이, users can feel the approaching exams and study diligently every day.

In addition to the countdown feature, 더데이 also offers inspirational quotes and uplifting articles on the home screen. These motivational messages can help users find the energy to keep studying when they feel tired.

더데이 also includes a simple community feature for exam takers. Whether preparing for 공무원 exams, 수능, or other English exams, students can connect with each other, share their anxieties, and exchange study tips.

Overall, 더데이 is a useful app for those who are preparing for various exams in Korea. Its countdown feature, motivational messages, and community function make it a handy tool for exam preparation.