1. How to install 해커스 ONE (해커스원) - 스마트 클래스 APK/XAPK file?
APK file: Tap on the downloaded APK file, and follow the on-screen prompts to complete the installation.
XAPK file: It's a compressed package containing an APK file and additional data files. You need a XAPK installer to install it. If you're using MEmu Android Emulator on PC, simply install the XAPK file directly into MEmu.