Phase 1 is a lean but future-proof MVP for a patent-pending acoustic app on iOS and Android. A full technical brief already exists and will be provided after an executed NDA; this posting only defines the outer boundaries of the MVP. Core MVP Scope • Account Flow — email-based registration and login • Audio Engine — compute a proprietary base tone (details post-NDA), display a tone ladder, and play pure synthesized sine waves with tap-to-play and loop playback without audible latency or artifacts • Performance — all audio must run in real time with efficient DSP and clean threading Architecture Requirements The codebase must be structured to allow later additions — new screens, a second computation mode using astrological inputs, and an optional ambient-audio layer — without major refactoring or rewrite. MVP is a single-screen experience, but must sit within a proper navigation stack from day one. Design Direction The interface should be intuitive and minimal: a clean home screen and one-tap access to the tone ladder. I will provide rough wireframes after NDA and welcome UI polish and motion suggestions. Tech & Delivery Notes • Native or well-supported cross-platform solutions are acceptable so long as audio timing remains precise • Clean architecture, modular components, and DI patterns will be reviewed at code handover • Git with meaningful commits and short milestone cycles is expected Deliverables Compilable iOS & Android repositories TestFlight build + internal APK for review Brief setup notes and high-level architecture diagram Once the milestones are agreed upon, I will provide the complete technical brief so you can finalize timeline and cost.