Stemify App - Split any song into stems — offline, on-device, free

Hey Product Hunt 👋 I built Stemify because every stem-splitter I tried wanted me to upload my tracks to some server, wait in a queue, and often pay per song. As someone who just wanted to pull the vocals out of a track to practice over, that felt backwards — why should my audio leave my phone at all? So Stemify runs the AI entirely on-device. You pick a song, and it separates it into vocals, drums, bass, and instruments right on your Android — no uploads, no account, no internet required. Your audio never leaves your phone, and it's free. The hardest part was getting the separation models to run fast on mobile hardware without melting the battery. A lot of the work went into native NEON-optimized FFT and squeezing the models down so it's actually usable, not a tech demo. Would love your feedback, especially: what would you use separated stems for? Practicing an instrument, karaoke, remixing, sampling? Curious what we should build next. 🎧