Yoban
Yoban (友伴, "friend companion") started from an observation: seniors love karaoke, but the apps are built for young users — tiny text, deep menus, busy screens.
A platform where seniors can sing together from home means real-time audio, RTC tokens that never sit in the client, and multi-platform releases that nobody has to cut by hand.
Flutter for the cross-platform client, Agora RTC for the stream with YouTube lyrics kept in sync, and a serverless backend on Azure Functions and Node.js that mints RTC authentication tokens so the channel stays encrypted. Releases run through GitHub Actions — APK builds and the web deploy to GitHub Pages.
Multi-platform deployment is fully automated, and token minting stays server-side so the client never holds a long-lived credential.