Thump — Your Heart Training Buddy

A native iOS 17+ and watchOS 10+ app that helps users understand their heart health trends through Apple Watch data, personalized insights, and gentle wellness nudges.

Demo

iOS App

https://github.com/cortexark/thump/raw/main/apps/HeartCoach/web/demos/ios-demo.mp4

Apple Watch

https://github.com/cortexark/thump/raw/main/apps/HeartCoach/web/demos/watch-demo.mp4

Website

https://github.com/cortexark/thump/raw/main/apps/HeartCoach/web/demos/website-demo.mp4

What It Does

Thump reads 9 key heart and fitness metrics from Apple Watch via HealthKit, runs trend analysis and correlation detection, then delivers personalized wellness nudges — all without storing health data on any server.

Key Features:

• Real-time heart health dashboard with cardio score, trend direction, and confidence badge
• 7-day / 14-day / 30-day trend charts for all tracked metrics
• Correlation engine that discovers relationships between your habits and heart health
• Personalized daily nudges based on your data patterns
• Apple Watch companion app with quick feedback and nudge tracking
• Weekly insight reports with actionable takeaways

Metrics Tracked:

Metric	Source	Watch Compatibility
Resting Heart Rate	HealthKit	Series 4+
Heart Rate Variability (SDNN)	HealthKit	Series 4+
Recovery Heart Rate	HealthKit	Series 4+
VO2 Max	HealthKit	Series 4+
Heart Rate (live)	HealthKit	Series 4+
Steps	HealthKit	Series 4+
Walking Minutes	HealthKit	Series 4+
Active Energy	HealthKit	Series 4+
Sleep Hours	HealthKit	Series 4+

All 9 metrics work on every Apple Watch model running watchOS 10+ (Series 4 and later). No Blood Oxygen or ECG features are used.

Architecture

apps/HeartCoach/
  iOS/                          # iPhone app
    ThumpiOSApp.swift           # App entry point
    Services/
      HealthKitService.swift    # HealthKit data queries
      SubscriptionService.swift # StoreKit 2 subscriptions
      NotificationService.swift # Local notifications + nudge scheduling
      ConnectivityService.swift # WatchConnectivity (iOS side)
      MetricKitService.swift    # Crash reporting via MetricKit
      AnalyticsEvents.swift     # Analytics event definitions
    ViewModels/
      DashboardViewModel.swift  # Main dashboard logic
      TrendsViewModel.swift     # Historical trend data
      InsightsViewModel.swift   # Correlations + weekly reports
    Views/
      DashboardView.swift       # Home screen
      TrendsView.swift          # Charts + time range picker
      InsightsView.swift        # Correlations + insights
      OnboardingView.swift      # Welcome + HealthKit + disclaimer
      PaywallView.swift         # Subscription tiers
      SettingsView.swift        # Profile + preferences
      Components/               # Reusable UI components
  Watch/                        # Apple Watch app
    ThumpWatchApp.swift         # Watch entry point
    Services/
      WatchConnectivityService.swift  # WatchConnectivity (watch side)
      WatchFeedbackService.swift      # Daily feedback persistence
    ViewModels/
      WatchViewModel.swift      # Watch UI state management
    Views/
      WatchHomeView.swift       # Main watch screen
      WatchNudgeView.swift      # Active nudge display
      WatchFeedbackView.swift   # Thumbs up/down feedback
      WatchDetailView.swift     # Metric detail screen
  Shared/                       # Code shared between iOS + Watch
    Models/
      HeartModels.swift         # HeartSnapshot, HeartAssessment, enums
    Engine/
      HeartTrendEngine.swift    # Trend analysis + cardio scoring
      CorrelationEngine.swift   # Cross-metric correlation detection
      NudgeGenerator.swift      # Personalized nudge selection
    Services/
      LocalStore.swift          # Encrypted UserDefaults persistence
      CryptoService.swift       # AES-GCM encryption via CryptoKit
      ConfigService.swift       # Feature flags + remote config
  web/                          # Landing page + legal
    index.html                  # Marketing landing page
    privacy.html                # Privacy policy
    terms.html                  # Terms of service
    disclaimer.html             # Health disclaimer
  project.yml                   # XcodeGen project spec
  Package.swift                 # Swift Package manifest

Tech Stack

Layer	Technology
UI Framework	SwiftUI
Health Data	HealthKit
Watch Comms	WatchConnectivity
Subscriptions	StoreKit 2
Charts	Swift Charts
Encryption	CryptoKit (AES-GCM)
Key Storage	Keychain Services
Crash Reporting	MetricKit
Notifications	UserNotifications
Project Gen	XcodeGen
Min iOS	17.0
Min watchOS	10.0
Swift	5.9

Privacy & Security

• Health data stays on-device — never uploaded to any server
• AES-GCM encryption at rest — health snapshots encrypted before storing in UserDefaults
• Encryption key in Keychain — kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly
• Anonymous usage analytics — no personally identifiable information collected
• No Blood Oxygen / ECG — avoids restricted HealthKit capabilities
• PrivacyInfo.xcprivacy — Apple privacy manifest included
• General wellness positioning — not a medical device, FDA general wellness exemption

Subscription Tiers

Tier	Price	Features
Free	$0	Dashboard, basic trends (7-day)
Coach	$4.99/mo or $39.99/yr	Extended trends (30-day), correlations, weekly reports, nudges
Family	$14.99/yr (annual only)	Coach features for up to 6 family members

Building

1. Install XcodeGen:

   brew install xcodegen

2. Generate the Xcode project:

   cd apps/HeartCoach
   xcodegen generate

3. Open in Xcode:

   open Thump.xcodeproj

4. Select the Thump scheme for iOS or ThumpWatch scheme for watchOS, then build and run.

Requirements:

• Xcode 15.0+
• iOS 17.0+ device or simulator
• watchOS 10.0+ Apple Watch (for watch features)
• Apple Developer account (for HealthKit entitlements)

Landing Page

Preview the marketing landing page locally:

cd apps/HeartCoach/web
python3 -m http.server 8080
# Open http://localhost:8080

Includes investor demo video (Thump_Landing_Page.mp4 / .gif).

Research Data

The data/ and scripts/ directories contain the Reddit trend analysis pipeline used for market research:

• scripts/crawl_reddit.py — Crawls r/AppleWatchFitness for posts, comments, and screenshots
• scripts/analyze_trends.py — Taxonomy labeling, trend aggregation, and report generation
• scripts/health_anomaly_engine.py — User-level anomaly detection prototype
• data/raw/ — Raw crawl outputs
• data/processed/ — Labeled trends, co-occurrence matrices, analysis summary

Run the full pipeline:

./scripts/run_pipeline.sh AppleWatchFitness

Quality Assurance

The codebase has been through 4 rounds of automated QAE/SDE review:

• Round 1: 55 bugs found and fixed (crashes, data races, missing entitlements, broken UI)
• Round 2: 8 regressions caught and fixed (compile errors, actor isolation)
• Round 3: 2 residual issues caught and fixed (Keychain race, thread safety)
• Round 4: 1 final issue caught and fixed (Combine subscription isolation)
• Result: Zero defects across all 84 files

Key fixes applied:

• Thread-safe @MainActor isolation on all ObservableObject classes
• NSLock serialization on CryptoService key generation
• HealthKit authorization handling aligned with Apple's privacy design
• StoreKit 2 purchase validation (family tier annual-only guard)
• Notification alert rate limiting with proper main-thread persistence
• WatchConnectivity delegate methods properly nonisolated with Task { @MainActor in } hops

License

Proprietary. All rights reserved.