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PrimeBeats: A Beautiful, Offline, Ad-Free Local Music Player for Android

Where #AI4Good began: PrimeBeats — an Amazon-Prime-Music-style player for the songs already on your phone. On-device Smart Radio, a real equalizer, lock-screen controls, background playback. No account, no ads, 100% offline.

ai4goodandroidreact-nativeexpomusicoffline

The first build of the #AI4Good series — one app a day, each free and built for good.

PrimeBeats — your music, beautifully local

Streaming turned music into something you rent. But most of us still have songs — actual files — sitting on our phones, and the built-in players that handle them are ugly, ad-riddled, or want an account. So the very first #AI4Good build was a quiet act of ownership.

What it is

PrimeBeats is “your music, beautifully local” — a polished, Amazon-Prime-Music-style player for the audio already on your device. What’s shipping:

  • Local library scan — finds every track and organizes it by album and folder, with instant search and a persistent mini-player on every screen.
  • Background & lock-screen playback — keeps playing when you switch apps or lock the phone, with full notification and lock-screen controls.
  • Android Auto — shows up in your car with icon-rich browsing (Made for You, Most Played, Recently Played, Playlists, Songs), Like / Loop / Smart-Radio buttons, two-way phone↔car sync, and voice (“play a song from PrimeBeats”), backed by a native media-browser service.
  • P2P music sharing — select songs and send them to another PrimeBeats user via the share sheet (Nearby Share, Bluetooth…); received tracks import into Shared with me and persist across updates.
  • Smart Radio (on-device ML) — an endless, fully-offline auto-queue that picks similar songs from the current track and your learned taste, with exploration and per-artist variety.
  • Equalizer & bass boost — a graphic EQ with device presets, per-band dB sliders, and a bass-boost control, all persisted.
  • Gestures & progressive seek — swipe the artwork to change track; double-tap and keep tapping a side to jump progressively further (+2, +2, +3, +4, +5s).
  • Make it yours — rename a song’s title & artist, fetch (iTunes) or upload custom album art, drag-to-reorder playlists and the up-next queue.

How it was built

PrimeBeats is Expo SDK 54 (React Native 0.81, React 19, TypeScript) — Expo chosen specifically so it runs in Expo Go for fast iteration. The interesting engineering is all in the details:

  • The single-player trick. Android background audio needs AudioPlayer.setActiveForLockScreen(...), which only exists on a player, not a playlist. So PrimeBeats keeps one app-lifetime AudioPlayer and manages the queue itself in a zustand store: playFrom(tracks, index) loads via player.replace({uri}), each change updates lock-screen metadata, and a playbackStatusUpdate listener mirrors position/duration into state and auto-advances on didJustFinish (respecting repeat mode).
  • On-device recommender, no cloud. Smart Radio blends content similarity (artist / album / folder / title keywords) with a taste profile that accumulates affinity from completed plays (+), early skips (−), and likes (++), minus a recency penalty, with per-artist diversity. The same signals derive Most Played / Recently Played / Made-for-You — fully offline, no extra ML runtime.
  • Album art without ID3. expo-media-library on this SDK doesn’t expose embedded artwork, so PrimeBeats renders deterministic gradient tiles from album/track initials (stable per album), with iTunes web-search and manual upload layered on top. ArtTile already accepts a real uri, so embedded-art extraction can drop in later.
  • Stack: expo-audio (ExoPlayer under the hood) · expo-media-library · React Navigation · zustand · AsyncStorage. Permissions are scoped tightly — READ_MEDIA_AUDIO, POST_NOTIFICATIONS, FOREGROUND_SERVICE_MEDIA_PLAYBACK — and RECORD_AUDIO is explicitly disabled; it’s playback-only. Pure logic is covered by a jest-expo suite.

One deliberate non-feature: a YouTube “audio-only + ad-blocking” mode was intentionally not built — extracting audio-only streams and blocking ads violates YouTube’s Terms of Service. The compliant path (official IFrame Player / Data API) is on the roadmap. Building for good includes what you refuse to build.

The good

Not every “AI for good” story is about a model — some are about dignity and control. PrimeBeats works with zero data, zero tracking, and zero cost, for people whose music lives on their phone, not in a subscription. It respects both your data plan and your privacy.

Try it

Next in the series → ActionCut. #AI4Good