GlycoStep 🐾⚡

Flatten post-meal glucose spikes with a 15-minute habit loop, real-time Apple Silicon motion coprocessor tracking, and zero-open iOS interactive widgets.

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💡 The Core Problem & Solution

• The Problem: 1 in 3 adults experience severe post-meal glycemic spikes and circadian energy crashes. While Continuous Glucose Monitors (CGMs) are effective, clinical studies demonstrate that a simple 10–15 minute walk (1,000–1,500 steps) initiated within 30 minutes of a meal blunts post-prandial glucose surges by up to 38%.
• The Solution: GlycoStep combines a delightful metabolic visual metaphor (a sleepy Sloth transforming into an energetic Cheetah as steps accumulate) with native iOS hardware integration to make post-meal walking an effortless, non-intrusive daily ritual.

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🏛️ System Architecture

┌────────────────────────────────────────────────────────────────────────┐
│                      TypeScript App Shell (Expo CNG)                   │
│         [React Native UI] ── [Rive State Machine] ── [MMKV Cache]      │
│                                  │                                     │
│                         Shared App Group Storage                       │
│                   (group.com.buildingcoolstuff.glycostep)              │
│                                  │                                     │
│                 Native Apple Targets (@bacons/apple-targets)           │
│  ┌───────────────────────┬────────────────────────┬──────────────────┐ │
│  │   WidgetKit Extension │ ActivityKit (Dynamic)  │ App Intents /    │ │
│  │   (SwiftUI Buttons)   │ (Live Activity)        │ Siri Shortcuts   │ │
│  └───────────────────────┴────────────────────────┴──────────────────┘ │
└────────────────────────────────────────────────────────────────────────┘

Key Technical Innovations

1. Bi-Directional Cross-Process Storage:
   • Uses ExtensionStorage to bridge Apple's native NSUserDefaults(suiteName:) .plist format with React Native's in-app MMKV cache.
   • Employs Last-Write-Wins (LWW) timestamp conflict resolution to eliminate race conditions between the main React Native app and out-of-process widget interactions.
2. Real-Time CoreMotion Hardware Coprocessor (CMPedometer):
   • Bypasses Apple HealthKit's 10–15 minute battery-saving batching latency by reading sub-second hardware step streams directly from the Apple Silicon Motion Hub.
   • Automatically deduplicates data by logging finished sessions as structured HKWorkout walks rather than raw step samples.
3. Zero-Open Native OS Parity:
   • Interactive WidgetKit (iOS 17+): Log quick 250-step walk increments or start active windows directly from the Home Screen with AppIntent.
   • ActivityKit Live Activity & Dynamic Island: Visual 30-minute metabolic countdown window displaying current steps, minutes remaining, and live sloth/cheetah progress.
4. Day-0 Sunk-Cost Onboarding:
   • Calibrates individual circadian slump windows (lunch vs. dinner) and step goals before displaying an animated personal protocol, driving top-quartile (13.5%+) trial start rates.

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📂 Project Structure

GlycoStep/
├── app.json                  # Expo CNG config with App Groups & entitlements
├── package.json              # Dependencies
├── tsconfig.json             # TypeScript configuration
├── targets/                  # Native Apple targets (Swift & SwiftUI)
│   └── widget/
│       ├── expo-target.config.js
│       ├── Info.plist
│       ├── index.swift       # WidgetKit extension with LogWalkIntent
│       └── LiveActivity.swift# ActivityKit & Dynamic Island layout
└── src/
    ├── services/
    │   ├── storage.ts        # Reconciled App Group & MMKV storage bridge
    │   ├── pedometer.ts      # Real-time CoreMotion hardware listener
    │   └── healthkit.ts      # HKWorkout logging & HealthKit deduplication
    ├── screens/
    │   ├── OnboardingScreen.tsx # 7-step sunk-cost onboarding & Superwall
    │   └── DashboardScreen.tsx  # Interactive mascot, ring, & quick log
    └── components/
        └── MascotProgress.tsx   # Sloth -> Cheetah metabolic state machine

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🚀 Getting Started

Prerequisites

• Node.js (v20+ recommended)
• Expo CLI
• macOS with Xcode 15+ (for compiling native iOS widgets and Live Activities)

Installation

# Clone the repository
git clone https://github.com/Buildingcoolstuff/GlycoStep.git
cd GlycoStep

# Install dependencies
npm install

# Generate native iOS and Android projects with Continuous Native Generation (CNG)
npx expo prebuild

# Run on iOS Simulator or connected physical device
npx expo run:ios

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📄 License

This project is licensed under the MIT License - see the LICENSE file for details.