Comparison

iCardio Workout Tracker vs Rhythm SYNC.

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

Head to head
About

iCardio Workout Tracker

This app helps you train smarter by using your heart rate data. It tracks workouts, provides real-time feedback, and integrates with wearables and Apple Health to offer insights into your performance and progress.

Highlights
  • Heart rate zone tracking
  • GPS route mapping
  • Voice coaching
  • Apple Watch & Health integration
  • Real-time workout sharing
  • Custom fitness assessments
Features
Read full description

iCardio – Smarter Heart Rate Training (Supports Bluetooth sensors, Apple Watch & Apple Health, and now AirPods Pro G3!) Track, train, and transform your fitness with iCardio, your all-in-one heart rate training companion. Whether you’re walking, running, cycling, or doing your favorite studio workout, iCardio helps you understand your heart, improve performance, and stay motivated. Train with Precision iCardio turns your heart rate into a powerful training tool. See your heart rate zones live as you work out, get instant feedback, and optimize every session to reach your goals faster — whether you’re training for endurance, weight loss, or general fitness. Connected Fitness, Simplified iCardio integrates seamlessly with Apple Watch and Apple Health, automatically syncing your workouts, calories, and key metrics like: * Heart Rate & Zones * Heart Rate Variability (HRV) * Resting Heart Rate Use iCardio as your fitness hub to bring together data from all your favorite Health-connected apps and devices — making it easier to track your overall wellness in one place. Comprehensive Tracking * GPS route mapping for outdoor workouts * Steps, calories, cadence, and power tracking * Custom Fitness Assessments to personalize zones * Routes & Routines to measure progress over time Key Features * Voice Coaching: Real-time cues to keep you on target * LiveTracking: Share your workout progress in real time * Goal Setting: Define and track personal fitness goals * Advanced Graphs & Analytics: Visualize heart rate, pace, and more * Web Sync: Review your data anytime, anywhere* Sleep, Weight, and Blood Pressure Device Compatibility Works with Apple Watch, Apple Health, and most Bluetooth fitness sensors — including Polar, Wahoo, Scosche, Viiiiva, POWR LABS, CooSpo, OrangeTheory, Garmin, and Moofit. Also supports power meters, cadence sensors, and Peloton® bikes. Free Features * Basic heart rate tracking * GPS & route tracking * Customizable voice coaching * Health metrics (weight, sleep, blood pressure) * Sync with Apple Health STAR Membership Unlock deeper insights with STAR Membership ($4.99/month or $29.99/year): * Advanced heart rate zone analysis * Speed and cadence sensor support * Personalized Fitness Assessments * Routes & Routines tracking * LiveTracking for real-time sharing * Group and community data sharing Subscription Details Payment is charged to your iTunes Account at purchase confirmation. Subscriptions renew automatically unless auto-renew is turned off at least 24 hours before the current period ends. Renewal is billed within 24 hours before renewal at $29.99/year or $4.99/month. Any unused trial period is forfeited upon subscription purchase. Manage or cancel your subscription in your Account Settings at any time. Privacy Policy: fitdigits.com/privacy-policy.html Terms of Use: fitdigits.com/terms-and-conditions.html* Ad-free experience and more Train smarter. Recover better. Live stronger. Download iCardio today and make every heartbeat count.

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.

Screenshots

iCardio Workout Tracker4 screens
Rhythm SYNC.4 screens

Verdict

The call

The clearest difference is review sentiment: iCardio Workout Tracker at 63% against Rhythm SYNC.'s 13%. iCardio Workout Tracker also leads on rating (4.8 vs 1.8) and update cadence (every 11 days vs every 3 months). Rhythm SYNC.'s advantage is in-app purchases (none vs 4) and iOS requirement (12.0 vs 17.6). On price, ads and device support 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. iCardio Workout Tracker sells 4 in-app purchases, starting at $4.99 per month. Rhythm SYNC. asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

iCardio Workout Tracker holds the better App Store score, 4.8 against 1.8. That said, the two scores are not equally well evidenced: iCardio Workout Tracker has 3.4K ratings behind it against 128, so its average is the more settled of the two. Written reviews point the same way: 63% of iCardio Workout Tracker's written reviews are positive against 13% of Rhythm SYNC.'s.

UpkeepUpdate frequency

iCardio Workout Tracker ships an update every 11 days, Rhythm SYNC. every 3 months. The most recent releases landed on September 23, 2026 and September 3, 2026 respectively.

Scorecard7 real differences · 3 level
iCardio Workout Tracker versus Rhythm SYNC.: the parameters behind the verdict, then further details
ParameteriCardio Workout TrackerRhythm SYNC.
PriceFreeFree
Rating4.8 (3.4K ratings) — better1.8 (128 ratings)
Positive reviews63.4% of reviews — better13.1% of reviews
Number of ratings3.4K — better128
Update frequencyEvery 11 days — betterEvery 3 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemiumFree — better
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPod
Requires iOS17.612.0 — better
Further details — not scored
Size85 MB47 MB
Age rating4+4+
DeveloperFitdigits IncScosche

Customer experience

iCardio Workout Tracker

All ratings3,366 ratings
Positive96.6%
Neutral1.2%
Negative2.3%
Written reviews290 reviews
Positive63.4%
Neutral6.6%
Negative30.0%

Rhythm SYNC.

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

User reviews

iCardio Workout Tracker

From 3.4K App Store ratings

What we love

  • 👍 Great app
  • 🚀 Accurate tracking
  • 💡 Customizable screens
  • 🚀 Reliable connection
  • 👍 Motivating

Room to improve

  • 🐛 Crashes and sync issues
  • 🔋 Battery drain
  • 🔒 Subscription model
  • 🐛 Inconsistent performance
  • 🐛 Sensor connection problems

Rhythm SYNC.

From 128 App Store ratings

What we love

  • ✅ Accurate heart rate readings
  • 🔋 Long-lasting device battery life
  • 🔄 Reliable device hardware
  • 📱 Simple and straightforward interface
  • 🔗 Works well with third-party apps (Peloton, Garmin, Apple Watch)

Room to improve

  • 🐛 Frequent Bluetooth connection failures
  • 🐛 App crashes and freezes regularly
  • ❌ App doesn't recognize connected devices
  • ⚠️ HRV mode difficult or impossible to access
  • 📊 Extremely limited app functionality

Bugs and requests

iCardio Workout Tracker

Reported bugs

3 issues
  • Garmin ANT+ connectivity issues
  • Incorrect calorie/distance tracking
  • Unreliable heart rate monitoring

Requested features

5 requests
  • Lap/split time tracking
  • Multi-user profiles
  • Treadmill/elliptical integration
  • More customization options
  • Improved Apple Watch integration

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

In-app purchases

4 purchases

iCardio Workout Tracker

Subscriptions3
  • Star Monthly$4.991 Month
  • Pro Plus$24.991 Year
  • Star$29.991 Year
One-time1
  • Plus$6.99
None

Rhythm SYNC.

No in-app purchases

Questions

Is iCardio Workout Tracker free?
iCardio Workout Tracker is free to download, with in-app purchases available.
Is Rhythm SYNC. free?
Rhythm SYNC. is free to download, with no in-app purchases.
Which has better reviews, iCardio Workout Tracker or Rhythm SYNC.?
iCardio Workout Tracker is rated higher. iCardio Workout Tracker averages 4.8 out of 5 from 3.4K ratings, while Rhythm SYNC. averages 1.8 from 128 ratings.
Do iCardio Workout Tracker or Rhythm SYNC. have ads?
Neither iCardio Workout Tracker nor Rhythm SYNC. shows ads.
Which is updated more often, iCardio Workout Tracker or Rhythm SYNC.?
iCardio Workout Tracker ships an update every 11 days, and Rhythm SYNC. every 3 months. Most recently, iCardio Workout Tracker was updated on September 23, 2026 and Rhythm SYNC. on September 3, 2026.

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