Comparison

Rhythm SYNC. vs Heartool

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Rhythm SYNC.

This app connects to heart rate monitors to display real-time data, manage activity modes, and track workout history. It allows for software updates and integrates with HealthKit for saving workout data.

Highlights
  • Connects to Rhythm 24 and Rhythm+ monitors
  • Manages activity modes and biometrics
  • Displays heart rate and battery level
  • Configures data sharing with other apps
  • Collects and downloads recorded activities
  • Performs software and firmware updates
  • HealthKit integration
Read full description

The award-winning Rhythm Heart Rate Monitors use patented technology to capture exceptionally accurate performance in both wet and dry conditions. This Scosche Rhythm Sync app: · Connects to Rhythm 24 and Rhythm+ Heart Rate Monitors · Manages Rhythm 24 activity modes and biometrics functionality: Heart Rate Only, Running, Cycling, Swimming, Heart Rate Variability, Duathlon, and Triathlon · Displays heart rate data from your Rhythm Monitors · Displays Rhythm battery level · Configures sharing with compatible heart rate tracking apps, fitness watches, bike computers, and fitness equipment, to stream your fitness-data in real time, track heart rate history, and more! · Collects Rhythm 24 recorded activities and has download capabilities · Allows for Rhythm Heart Rate Monitors software and firmware updates · HealthKit integration which allows you save workout data recorded on the sensor.

About

Heartool

Transform your phone into a fitness tracker to monitor workouts with live heart rate data. Analyze training progress with professional charts and gain insights into your health and cardio condition. Integrates with wearable devices and Apple Health.

Highlights
  • Live heart rate tracking
  • HRV biofeedback
  • Cardio health analysis
  • Workout progress charts
  • Calorie burned tracking
  • Health data synchronization
Read full description

Turn your phone into a fitness tracker with Heartool, to record your workouts with heart rate data. It is a concise and most accurate way to measure your training progress, to reach your fitness goals. Working with wearable devices to train in real time. For heart rate sensor recommend: www.fitcare.com Heartool gives you: 1.Tracking your live heart rate at right intensity for maximum results. With professional chart records, users could see their exercise effects when and after their training. 2.HRV biofeedback. Based on the heart rate sensor R-R interval data, together with professional algorithm, Heartool could help you to know your health and training status. 3.Cardio health condition. Based on the waveform (ECG) data and through the professional algorithm, Heartool could help you to discover hidden heart health hazards in time. HealthKit 1. Heartool Will share the record (heart rate) to the Apple's health applications after each exercise 2. Because the privacy of your health data is very important, the user must agree to authorize Apple Health in "Set up -> Authorization" in the Heartool APP before sharing the heart rate data to your Apple Health app. 3. Heartool Connect to a healthy feature supports iPhone 6 and above devices, and the system version is iOS9.0 and above. Main features: 1.Personalized heart rate zone setting, sync to the training sensor. 2.Calories burned checking based on the workouts. 3.Storing data import. If sensors not connected to the App, data could sync to the App after training. 4.Daily health management with cardio status and stress reflect. 5.Health data record, review a summary of the result from your entire workout history.

Screenshots

Rhythm SYNC.4 screens
Heartool4 screens

Verdict

The call

The clearest difference is rating: Heartool at 3.1 against Rhythm SYNC.'s 1.8. Heartool also leads on review sentiment (21% vs 13%). Rhythm SYNC.'s advantage is ratings volume (128 vs 14). On price, update cadence, ads and in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Heartool holds the better App Store score, 3.1 against 1.8. That said, the two scores are not equally well evidenced: Rhythm SYNC. has 128 ratings behind it against 14, so its average is the more settled of the two. Written reviews point the same way: 13% of Rhythm SYNC.'s written reviews are positive against 21% of Heartool's.

UpkeepUpdate frequency

Rhythm SYNC. ships an update every 3 months, Heartool every 4 months. The most recent releases landed on September 3, 2026 and September 18, 2026 respectively.

Scorecard3 real differences · 7 level
Rhythm SYNC. versus Heartool: the parameters behind the verdict, then further details
ParameterRhythm SYNC.Heartool
PriceFreeFree
Rating1.8 (128 ratings)3.1 (14 ratings) — better
Positive reviews13.1% of reviews21.2% of reviews — better
Number of ratings128 — better14
Update frequencyEvery 3 months — betterEvery 4 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPod
Requires iOS12.012.0
Further details — not scored
Size47 MB24 MB
Age rating4+12+
DeveloperScoscheShenzhen Onecoder Technology Co., Ltd.

Customer experience

Rhythm SYNC.

All ratings128 ratings
Positive16.4%
Neutral1.6%
Negative82.0%
Written reviews99 reviews
Positive13.1%
Neutral1.0%
Negative85.9%

Heartool

All ratings14 ratings
Positive42.9%
Neutral14.3%
Negative42.9%
Written reviews52 reviews
Positive21.2%
Neutral9.6%
Negative69.2%

Bugs and requests

Rhythm SYNC.

Reported bugs

17 issues
  • App fails to detect device despite Bluetooth connection
  • Bluetooth connection drops frequently during workouts
  • App crashes on startup (splash screen freeze)
  • Firmware update fails repeatedly
  • HRV readings not displaying or accessible
Show 12 more
  • Custom heart rate zones not applied to recordings
  • Battery level shows as zero or incorrect
  • Settings menu items non-functional or unresponsive
  • App loses connection when device syncs with other apps
  • Data disappears when monitor disconnects
  • Export to CSV ignores custom zones
  • App crashes when attempting to share workout data
  • Last mode setting not remembered between sessions
  • Unable to modify personal details (height, weight, birthday)
  • Incompatibility with iPhone X and newer models
  • Firmware update window won't open
  • App incompatible with iOS 11 and newer versions

Requested features

12 requests
  • HRV (Heart Rate Variability) mode that actually works
  • Comprehensive workout history and logging
  • Data export to multiple health apps (MyFitnessPal, TrainingPeaks, etc.)
  • Customizable heart rate zones that persist
  • Batch download and export of multiple files
Show 7 more
  • Auto-sync feature when device is detected
  • Detailed analytics and charts
  • Better user profile settings (height, weight, age)
  • Dark mode option
  • Improved troubleshooting and help documentation
  • Ability to delete saved connections to health apps
  • Support for multiple languages in documentation

Heartool

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Rhythm SYNC.

No in-app purchases

None

Heartool

No in-app purchases

Questions

Is Rhythm SYNC. free?
Rhythm SYNC. is free to download, with no in-app purchases.
Is Heartool free?
Heartool is free to download, with no in-app purchases.
Which has better reviews, Rhythm SYNC. or Heartool?
Heartool is rated higher. Rhythm SYNC. averages 1.8 out of 5 from 128 ratings, while Heartool averages 3.1 from 14 ratings.
Do Rhythm SYNC. or Heartool have ads?
Neither Rhythm SYNC. nor Heartool shows ads.
Which is updated more often, Rhythm SYNC. or Heartool?
Rhythm SYNC. ships an update every 3 months, and Heartool every 4 months. Most recently, Rhythm SYNC. was updated on September 3, 2026 and Heartool on September 18, 2026.

Other comparisons