Most focus apps use static timers or game engines. InkZen uses Metal Compute Shaders. We built a custom fluid dynamics engine to simulate real carbon ink drying on rice paper—a non-repeating visual anchor for flow. Key Differentiators: 💧 Real-time Physics: Ink flow is calculated, not pre-rendered. 🔊 Procedural Audio: Rain & bells are generated stochastically, never looping. 🏝️ Native iOS: WidgetKit & Live Activities integration. 🌸 Divine Will: Physics-based decision making.