# NightGuard: Sleep & Habits — Smart Sleep & Habit Tracker

> AI-driven sleep analysis and habit improvement app with HealthKit integration. (iPhone/iPad app by 符垚 秦.)

- Source: https://appshunter.io/ios/app/nightguard-sleep-and-habits/id6754812386 (this page in markdown: same URL + `.md`)
- Developer: [符垚 秦](https://appshunter.io/developer/1826299020)
- Category: Health & Fitness, Lifestyle
- Price: Free with in-app purchases
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 12+
- Requires: iOS 17.6 · 7 MB
- Languages: American English, Chinese (Simplified, China)
- Released: 2025-11-18
- Data updated: 2026-06-01
- Monetization: freemium
- User reviews in markdown: https://appshunter.io/ios/app/nightguard-sleep-and-habits/id6754812386/reviews.md

## What is NightGuard?

NightGuard is a professional AI-powered sleep health app that helps you deeply understand your sleep and scientifically improve your rest. By integrating Apple HealthKit and WeatherKit with on-device deep learning models, NightGuard delivers clinical-grade sleep analysis and personalized improvement plans.

Key Features:

  • Hybrid AI Sleep Scoring: Combines a CoreML Transformer deep learning model with a lightweight neural network to generate precise sleep quality scores (0-100) across multiple dimensions including sleep stages, duration, and efficiency — all processed entirely on your device

  • Comprehensive Health Tracking: DeepHealthKit integration for full physiological monitoring including heart rate, heart rate variability (HRV), blood oxygen saturation (SpO2), respiratory rate, and body temperature

  • Smart Data Source Management: Choose which device's sleep data to analyze, ensuring your scores are based on the most accurate source

  • Multi-Range Trend Analysis: Day, week, month, 6-month, and yearly views to visualize sleep patterns and long-term trends at a glance

  • Environmental Impact Analysis: WeatherKit integration to quantify how temperature, humidity, and other environmental factors affect your sleep

  • AI Personalized Insights: Dynamically adjusts scoring standards based on your age, gender, and historical data, delivering actionable sleep improvement recommendations

  • Privacy-First Design: All AI inference runs locally on your device — your health data never leaves it. Secure iCloud (CloudKit) sync keeps your data consistent across all your devices

NightGuard — Your personal sleep scientist, guarding every night with AI.

## Key features

- Hybrid AI Sleep Scoring
- Comprehensive Health Tracking
- Smart Data Source Management
- Multi-Range Trend Analysis
- Environmental Impact Analysis
- AI Personalized Insights
- Privacy-First Design

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Monthly Subscription | $4.99 | per month |
| AI Enhanced Quarterly Subscription | $9.99 | per 3 months |
| AI Enhanced Annual Subscription | $29.99 | per year |



## Frequently asked questions about NightGuard

### What is NightGuard's sleep scoring based on?

NightGuard uses a hybrid AI approach, combining a CoreML Transformer deep learning model with a lightweight neural network. This system generates precise sleep quality scores (0-100) by analyzing sleep stages, duration, and efficiency, all processed locally on your device.

### What health metrics does NightGuard track?

NightGuard integrates deeply with Apple HealthKit to monitor physiological data including heart rate, heart rate variability (HRV), blood oxygen saturation (SpO2), respiratory rate, and body temperature.

### How does NightGuard personalize sleep insights?

The app dynamically adjusts its scoring standards based on your age, gender, and historical data. This allows NightGuard to deliver actionable sleep improvement recommendations tailored specifically to you.

### Does NightGuard have ads?

No, NightGuard is ad-free. The app focuses on providing a seamless and uninterrupted user experience for sleep analysis and improvement.

### What subscription plans are available for NightGuard?

NightGuard offers a Monthly Subscription at $4.99/month with a 3-day free trial, an AI Enhanced Quarterly Subscription for $9.99/quarter with a 7-day free trial, and an AI Enhanced Annual Subscription for $29.99/year with a 7-day free trial.

### How does NightGuard handle user privacy?

NightGuard is designed with privacy as a priority. All AI inference runs locally on your device, ensuring your health data never leaves it. Secure iCloud sync is available for data consistency across devices.

### Can NightGuard analyze sleep data from different devices?

Yes, NightGuard features Smart Data Source Management, allowing you to choose which device's sleep data to analyze. This ensures your sleep scores are based on the most accurate available source.

### How frequently is NightGuard updated?

The latest version of NightGuard is V3.1.0, and it was last updated on February 9, 2026. This indicates a commitment to regular updates and improvements.

## Version history (last 5 releases)

### V3.1.0 — 2026-02-09

1. A Fresh Visual Identity
  - Modern color upgrade: The app's theme has been refreshed with deep Indigo & Purple tones, delivering a more premium, immersive nighttime guardian experience.
  - Full Dark Mode and Light Mode support — the interface looks stunning in any environment.
  - More natural time display: Optimized time formatting throughout the app for clearer, more intuitive readability.

2. Smarter Sleep Analysis
  - New sleep data source selector: Choose which device's sleep data to analyze for more precise results.
  - New weekly view: See your sleep quality trends at a glance and easily spot patterns in your routine.
  - AI sleep insights fully upgraded — faster generation with more personalized recommendations.

3. Data Accuracy & Privacy
  - Fixed display logic for sleep records and physiological metrics, ensuring more consistent and reliable feedback for SpO2, sleep duration, and other key data.
  - Enhanced privacy protection: The underlying logging system has been fully upgraded with privacy redaction to safeguard your sensitive health data more rigorously.

4. Lighter & Faster
  - Major performance optimization: Removed thousands of lines of redundant code for a smaller footprint and faster launch.
  - Resolved dashboard stuttering and redundant refresh issues in certain scenarios.
  - Fixed weekly chart display, subscription lock state, and other known issues.

### V3.0.1 — 2026-02-01

1. Fixed subscription bugs
2. Updated the UI style of some pages

### V3.0.0 — 2026-01-26

NightGuard 3.0.0 - Cloud AI & New Sync Engine

This major update brings professional AI insights and a completely rebuilt data core for ultimate performance.

MAJOR FEATURES
- Cloud AI Analysis: Connect to our advanced cloud engine for deeper, personalized sleep insights.
- All-New Sync Engine: We rebuilt our data layer from the ground up using Anchor-based syncing. Experience significantly faster loading, improved reliability, and lower battery usage.
- Weekly AI Summary: New weekly trends looking at your long-term sleep health.

IMPROVEMENTS
- Enhanced Startup: A smoother, polished launch experience with better progress feedback.
- Background Reliability: Fixed background processing issues to ensure your data stays up-to-date.
- Visual Polish: Refined UI for reports and calendar views.

### V2.2 — 2026-01-14

Version 2.2 - Smarter Insights, Silky Smooth

In this update, we focused on refining every detail to make NightGuard not just smarter, but faster and more responsive to your life.

[ Insights That Understand You ] AI is now more human-aware:

Beyond Just Scores: NightGuard can now detect "Social Jet Lag", "Sleep Debt", and "Travel Jet Lag". Receive tailored advice whether you're recovering from a weekend party or a long flight.
Score Transparency: Added a "Data Confidence" indicator. Instantly see the data quality behind every sleep score—trust every number.

[ Faster & Smoother ] We've rebuilt the app's core engine:

Instant Response: The Sleep Dashboard has been re-engineered for speed. Scrolling through history and loading daily data feels smoother than ever.
Seamless Sync: Data syncs across your devices faster and more reliably.

[ Refinements ]

Fixed various minor issues to improve overall stability and user experience.

### V2.0 — 2025-12-06

1.Updated local AI weights
2.Optimized homepage UI
3.Fixed known CloudKit issues
4.Fixed several known issues

## Apps similar to NightGuard

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## More apps by 符垚 秦

- [IronSets](https://appshunter.io/ios/app/ironsets/id6758879385)
- [DidntRead](https://appshunter.io/ios/app/didntread/id6759222453)

All apps by 符垚 秦: https://appshunter.io/developer/1826299020

## Related topics

[night guard](https://appshunter.io/ios/topics/night-guard)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-01.*