Worked on the keiyoushi/extensions-source repository to deliver a targeted security enhancement focused on user authentication and session management. Addressed a bug affecting login status detection by refining the logic to accurately identify authenticated users and securely handle session IDs, thereby preventing unauthorized content access. The solution was implemented using Kotlin and leveraged API integration skills to validate the authentication flow, specifically testing against the NicovideoSeiga login process. Updated the version code to reflect these security and authentication improvements. The work emphasized robust mobile development practices, ensuring that session validation and user access controls were reliable and ready for production release.