NicotinD is a self-hosted music server, and this is its Android client. You run the server on your own machine; the app connects to it and streams your library. There is no NicotinD account, no cloud service, and nothing to sign up for — the only server the app talks to is the one whose address you give it. You will need a NicotinD server before this app is useful. It runs in one Docker container on anything from a spare laptop to a NAS. <b>What it does</b> * Browses and streams your library — artists, albums, songs, genres, with cover art and full tag metadata. * Plays in the background with lock-screen and notification controls, and keeps playing when you switch apps or turn the screen off. * Saves tracks for offline playback, so a commute without signal still has music. * Metadata-driven radio that picks what comes next from BPM, musical key, genre and mood similarity rather than from a recommendation service. * Synced lyrics with a karaoke-style vocal-mute option. * Listening history and stats, native and auto-generated playlists. * Casts to another device running NicotinD, or to Chromecast and DLNA hardware. * Multi-user, with per-user settings on one shared library and roles from listener to admin. <b>Privacy</b> The app talks to your server and nothing else. No analytics, no advertising identifiers, no third-party SDKs. Your listening history lives in your own database. <b>About this build</b> This is the same APK the project publishes on its GitHub releases — one build, no F-Droid-only variant. It contains no proprietary library of any kind. Installed from F-Droid, the app updates through F-Droid, and its own in-app update button hides itself. That button exists for people who install the APK directly, where it is the only way to update; the app asks Android who installed it and removes the control when a store did. This is why the app declares the "install unknown apps" permission even though F-Droid will never use it here. There is no QR-code pair