Heart Analyzer vs Duffy
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Heart Analyzer
Gain deep insights into your heart health using data from your Apple Watch. Visualize trends, analyze metrics like Cardio Recovery and Heart Rate Zones, and generate detailed PDF reports. Offers advanced features and privacy-focused data handling.
- Dashboard with daily summaries
- Visualized heart rate and health data charts
- Health vital trend assessment
- Cardio Recovery and Heart Rate Zone analysis
- Exportable PDF heart reports
- ECG data comparison
- HRV rMSSD and heart rate calibration
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Heart Analyzer helps you track Heart Rate, HRV, Resting Heart Rate, Cardio Recovery, Sleep and ECG trends using Apple Watch. Analyze your Health data with advanced charts, insights, Heart Reports, widgets and detailed heart analytics powered by Apple Health. Set your own high and low heart rate alerts, take control of your HRV data in the new HRV Center, and see your sleep in detail with multiple sessions, naps and time out of bed. ------------------------------------------------ ■ Simple PRIVACY ------------------------------------------------ ◎ No third party analytics ◎ No data ever leaves your device ◎ No modifications to your health data ------------------------------------------------ ■ FEATURES ------------------------------------------------ ◎ The Dashboard - Where you can swipe between days, scroll through summaries and tap into the details ◎ Charts - Heart Rate and other Health data visualized through metrics and trends of any given day ◎ Insights - Effortlessly assess your Health Vital trends ◎ Heart Rate Alerts - Choose your own high and low heart rate limits, set mute times, and opt to be notified only on sustained changes ◎ HRV Center - Control the quality and context of the Heart Rate Variability data behind your trends ◎ Sleep - Multiple sleep sessions, naps and time out of bed, with your heart rate through the night ◎ Analytics Plus - Gain a unique understanding of important metrics such as Cardio Recovery, Heart Rate Zones and plenty more ◎ Heart Reports - Generate and export tailored PDFs including a large selection of metrics with custom timescales and password protection support ◎ Bookmarks - Highlight specific days of interest, make notes on relevant details ◎ Widgets - Interact with your Home Screen and track your Heart Rate, Resting Heart Rate trends and more at a glance ◎ ECGs - Compare and analyze data recorded by Apple Watch ◎ Advanced features - Including HRV rMSSD, Heart Rate Calibration, Custom Heart Rate Zones, Smart Heart Rate Recovery and more ------------------------------------------------ ■ APPLE WATCH ------------------------------------------------ ◎ A re-designed app showing your Heart Rate over the day ◎ Heart Rate Alerts on your wrist, with no complication needed on your watch face ◎ Charts with you on the go for Move, Exercise, Cardio Points, HRV, Blood Oxygen Saturation and Resting Heart Rate ◎ Workouts right on your wrist, tap into the detail as soon as you finish your exercise ◎ Customizable complications to keep you up to date with your Heart Rate and also support for Blood Oxygen Saturation, Heart Rate Variability and Resting Heart Rate trends HEALTH SUPPORT INCLUDES: - Heart Rate - Resting Heart Rate - Blood Pressure (Systolic & Diastolic) - Electrocardiogram (ECG/EKG) - Blood Oxygen Saturation (SPO2) - Cardio Fitness (VO2Max) - Heart Rate Variability (SDNN & rMSSD) - Respiratory Rate - Breathing Disturbances - Workouts - Sleep Times, Sessions & Naps - Heart Rate Recovery - Apple Fitness & Activity - High & Low Heart Rate Notifications Heart Analyzer Premium is available as an optional monthly or annual subscription. You can also choose a one-time Lifetime Access purchase. Payment will be charged to your Apple ID account. Subscriptions automatically renew unless cancelled at least 24 hours before the end of the current billing period. You can manage or cancel your subscription at any time in your App Store account settings. Additional Terms of Use: https://www.helixapps.co.uk/heart-analyzer-terms-of-use Please Note: - Heart Analyzer integrates with the Apple Health App to read your Heart Rate and other Health data - Heart Analyzer is available on iPad with iCloud sync for Apple Health data enabled. However, you still need an iPhone with a paired Apple Watch to generate Health data to display in Heart Analyzer - To get the most out of Heart Analyzer, an iPhone with a paired Apple Watch is required
Duffy
This app displays your daily step count directly on your Apple Watch face as a complication. It offers a full watch app for detailed stats and goal notifications, plus a companion iPhone app for deeper data analysis and trends. Access your fitness data at a glance without opening the Activity app.
- Watch face complication for step count
- Full watch app for steps, flights, distance
- Daily step goal notifications
- Companion iPhone app for trends
- HealthKit data integration
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Duffy provides quick access to your step count directly on your Apple Watch face as a complication. I was surprised to find that a steps complication wasn’t included on Apple Watches out of the box. Being a veteran iOS developer, I decided to build one in my spare time. I really loved my prototype version and thought there were more people who would love it too. So I put in the extra effort to release it to the App Store for everyone! Duffy is completely free, has no ads, and is even open source so if you’re also a developer, you can help me enhance it. Duffy is a simple app, but it will probably turn into the most used app on your Apple Watch. No more opening the Activity app and scrolling around to find your steps. It’s now available at a glance. Duffy is more than just an elegant Apple Watch complication. Use the full watch app for easy access to your steps, flights climbed and distance travelled for today and the past week. Set a daily steps goal and be notified on your watch when you reach it. The companion iPhone app provides the same access to your steps, flights and distance on a much larger, easier-to-read surface while also allowing you to dig deeper into your data to see trends and statistics over time. Duffy reads the steps, flights climbed, distance travelled, and activity energy from your iPhone and Apple Watch from the Health app (via the HealthKit API).
Screenshots
Verdict
The clearest difference is update cadence: Heart Analyzer at weekly against Duffy's every 5 months. Heart Analyzer also leads on ratings volume (22K vs 757). On price, rating, review sentiment and ads there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Heart Analyzer sells 7 in-app purchases, starting at $3.99 per month and Duffy sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 4.7 for Heart Analyzer against 4.7 for Duffy. That said, the two scores are not equally well evidenced: Heart Analyzer has 22K ratings behind it against 757, so its average is the more settled of the two. Written reviews split almost evenly too, at 84% and 84% positive.
Heart Analyzer ships an update weekly, Duffy every 5 months. The most recent releases landed on October 18, 2026 and October 16, 2026 respectively.
| Parameter | Heart Analyzer | Duffy |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (22K ratings) | 4.7 (757 ratings) |
| Positive reviews | 84.2% of reviews — better | 83.7% of reviews |
| Number of ratings | 22K — better | 757 |
| Update frequency | Weekly — better | Every 5 months |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Devices | iPhone, iPad, Apple Watch — better | iPhone, Apple Watch |
| Requires iOS | 17.5 — better | 18.6 |
| Further details — not scored | ||
| Size | 54 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | Helix Apps LTD | Think Tank Productions |
Customer experience
Heart Analyzer
Duffy
Bugs and requests
Heart Analyzer
Reported bugs
3 issues- Premium features not working as expected
- Syncing issues between iPhone and Apple Watch
- Oxygen level tracking not functioning properly
Requested features
4 requests- Add blood pressure monitoring
- Allow generating reports for current month
- Improve ECG interpretation guidance
- Add option to customize Apple Watch complications
Duffy
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Heart Analyzer
- Monthly$3.991 Month
- Annual$19.991 Year
- Data Plus$9.99
- Reports Plus$9.99
- Analytics Plus$9.99
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- Complete Premium$24.99
- Lifetime Access$49.99
Duffy
- Tip $1$0.99
- Tip $2$1.99
- Tip $3$2.99
Show 1 moreShow fewer
- Tip $5$4.99









