Rehearsal recordings from one phone are usually muddy - the loudest or closest instrument overpowers the other. PolyMic fixes this with phones you already own. Place a phone next to each instrument, tap record on any of them, and every device records in sync. Mix levels and pan on your phone, export a polished mix, or take the stems into Logic, Ableton, Pro Tools or any other DAW. No interface, mixer or laptop.