ST Unitas has developed a free app for Android called "3분이면 복습 끝 암기강훈련" that aims to help students memorize vocabulary in a fun and efficient way. It offers four different tests with randomly generated questions, which ensure that the same question does not appear more than once. The app is designed to help users review important words quickly and easily, with the ability to save unfamiliar words for later review. The app also includes an MP3 feature that reads the vocabulary words and their meanings aloud, which can help users memorize them subconsciously.

However, the app requires access to the device's storage, phone, and contacts. It is important to note that the app only uses the phone permission to check the call status during playback, and the contacts permission is only used to verify personal identification information for notification purposes. It is recommended that users upgrade their Android OS to version 6.0 or higher to take advantage of the ability to distinguish between required and optional permissions.