Tags: flutter, dart, opensource, music, mobile I was tired of paying Spotify $10/month and still getting ads on free tiers. So I built my own. HeySongers is a free, open-source music streaming app for Android and Windows that streams from YouTube Music, supports offline downloads, and has zero ads. Here's how it works under the hood. The Stack Layer Technology Frontend Flutter + Dart Music Source dart_ytmusic_api + youtube_explode_dart Audio Engine media_kit + audio_service for background playback State Management provider Local Storage hive for playlists + sqflite for offline tracks Networking dio with caching via cached_network_image UI shimmer for loading, phosphor_flutter for icons, google_fonts for typography How Music Streaming Works The core challenge was streaming audio from YouTube without any official API. Step 1: Search & Metadata dart_ytmusic_api handles search queries. It returns song metadata — title, artist, album art, duration, and most importantly, the video ID. Step 2: Extracting Audio Streams youtube_explode_dart takes that video ID and extracts the raw audio stream URL. It parses the YouTube player response to get the adaptive audio format (usually opus or m4a). Step 3: Playback media_kit handles the actual audio rendering. It's lightweight, supports gapless playback, and works reliably across Android and Windows. Step 4: Offline Downloads When a user taps download, the audio stream is fetched via dio and written to local storage using path_provider. hive indexes the downloaded files so the app can serve them instantly in offline mode. Background Playback (The Hard Part) Mobile apps that stop playing when you switch apps are annoying. Flutter's audio_service makes this work by running a headless isolate that survives app suspension. The audio controls (play/pause/seek) sync with the Android notification shade and Windows taskbar via platform channels. The UI I wanted it to feel premium despite being free. Dark theme by default with an optional light theme. shimmer loading skeletons make searches feel instant. Album art loads lazily via cached_network_image so scrolling through playlists is smooth. Biggest Challenge The YouTube streaming endpoints change frequently. youtube_explode_dart handles most of it, but I had to add retry logic and fallback formats because not all videos serve the same audio codecs. Some return opus, some m4a, and the extraction logic needs to handle both. What's Next AI-powered recommendations Lyrics sync Equalizer iOS & Linux support Try It HeySongers is 100% open source. No premium tier, no ads, no tracking. Just music. ⭐ Star on GitHub: 📥 Download: Built with ❤️ by Ruthvik Pedapondara ( @geethudinoyt )