Stash

Stash is an offline-first Android music player that syncs your liked songs, playlists, daily mixes, and discover mixes from both Spotify and YouTube Music into a single unified local library.

Your Spotify + YouTube Music library, on your phone, in FLAC.

Stash mirrors your Spotify and YouTube Music libraries to your Android phone. You connect each service, pick the playlists and mixes you want, and Stash either downloads them as real FLAC files for offline playback or surfaces them as a streaming index so you can stream tracks without filling up your storage. Same library, two modes, one tap to switch.

Features
● Offline everything — tracks download as high-quality lossless audio
● Bulletproof matching — finds the right version of tracks 99% of the time
● Custom playlists — create your own playlists and save tracks to them from anywhere.
● Spotify & YT sync preferences — choose exactly which playlists, liked songs, daily mixes, and discovery mixes to sync. Individual toggles for each. Don’t want Daily Mix 3? Turn it off.
● Expanded Spotify mix detection — Release Radar, Discover Weekly, On Repeat, Daylist, Repeat Rewind, Time Capsule, and Daily Mixes 1-6 are all automatically detected when available. Each gets its own toggle.
● Refresh vs Accumulate sync modes — mixes can either replace their contents each sync (Refresh) or stack new tracks on top of what’s already there (Accumulate). Your call.
● Parallel downloads — 8 simultaneous tracks. Background sync runs as a foreground service so it actually finishes with the phone locked.
● High-res album art
● Automatic update notifications — checks GitHub for new releases daily and notifies you when one is available.
● Full equalizer — 5-band EQ with presets, bass boost, and virtualizer
● Spotify sign-in built in — just log into Spotify inside the app
● Private by design — credentials encrypted with AES-256-GCM, no servers, no telemetry, nothing leaves your phone
● Free and open source — no subscriptions, no ads, GPL-3.0

There’s no Stash account. No subscription. No ads. No analytics. Your credentials live on your phone, encrypted, and the only network traffic Stash makes is to Spotify and YouTube themselves.