Comparison

Rhythm SYNC. vs Spren Body Composition Scanner

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

Spren Body Composition Scanner

This app uses your smartphone to measure body fat percentage, BMI, and body composition. It provides detailed health reports, tracks weight loss, and offers personalized nutrition plans, acting as a smart scale alternative with research-grade analysis.

Highlights
  • Body fat percentage measurement
  • BMI calculator
  • Body composition analysis
  • Weight tracking
  • Personalized nutrition planning
  • Multi-page PDF reports
Features
Read full description

Revolutionize your fitness journey with Spren, the ultimate health app and fitness app: • Advanced BMI-Calculator & Body Fat Calculator: Use your smartphone as a body scan tool for accurate body fat percentage and BMI measurements, results are comparable to DEXA scans. • Comprehensive Health App Reports: As a sophisticated body tracker and body measurement tracker, Spren provides detailed insights including body fat percentage, BMI analysis, body composition breakdown • Research-Based Fitness Tracker: Align your results with healthy ranges from extensive research, similar to DEXA scan standards. • Weight Tracker & Weight Loss Tracker: Monitor your weight and track weight loss effectively, going beyond what traditional smart scales offer. • Body Composition Analysis: Understand the nuances of body composition, not just BMI, using Spren as your personal fitness tracker and health app. • Smart Scale Alternative: Experience the convenience of a smart scale combined with the detailed analysis of a professional-grade body fat calculator, scanner, and BMI calculator. • Personalized Nutrition Planning: Set targeted goals and begin tracking toward them today with a data-backed nutrition plan created just for your needs. Get a multi-page PDF report that includes: • Body fat % • Fat mass • Lean mass • A/G fat ratio • Resting metabolic rate Plus, see how your results compare to healthy and optimal ranges from published research. The technology seems magical, but the science behind the imaging algorithm has been validated by several independent peer-reviewed studies, making research-grade body composition analysis accessible to anyone with a smartphone. Spren is more convenient than comparable methods like DEXA and underwater weighing, and the results are more comprehensive and accurate than bathroom scales or other apps. Focusing on weight loss alone may not be helping you achieve your deeper health goals. If you're losing lean mass versus body fat, you're not getting fitter. With Spren you will: • Avoid the confusion and frustration of false plateaus. • Help understand if your nutrition, fitness, and recovery programs are working for you. • Ensure that you're making progress toward your deeper health goals. Discover the true progress of your fat loss, lean gains, metabolic health, and longevity with Spren's research-grade body composition analysis — go beyond the scale and take control of your health journey. Sign up for one of our comprehensive wellness subscriptions and start your journey today. You can cancel at any time. The results provided by this app are intended for informational purposes only and should not be used as a basis for any medical treatment or diagnosis. Terms of service: https://www.spren.com/terms-conditions Privacy policy: https://www.spren.com/privacy-policy Your data is processed securely in the cloud. getsupport@spren.com

Screenshots

Rhythm SYNC.4 screens
Spren Body Composition Scanner4 screens

Verdict

The call

The clearest difference is rating: Spren Body Composition Scanner at 4.7 against Rhythm SYNC.'s 1.8. Spren Body Composition Scanner also leads on review sentiment (46% vs 13%) and update cadence (every 9 days vs every 3 months). Rhythm SYNC.'s advantage is in-app purchases (none vs 14) and iOS requirement (12.0 vs 17). 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. Spren Body Composition Scanner sells 14 in-app purchases, starting at $10.49 per month. Rhythm SYNC. asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Spren Body Composition Scanner holds the better App Store score, 4.7 against 1.8. That said, the two scores are not equally well evidenced: Spren Body Composition Scanner has 1.5K ratings behind it against 128, 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 46% of Spren Body Composition Scanner's.

UpkeepUpdate frequency

Rhythm SYNC. ships an update every 3 months, Spren Body Composition Scanner every 9 days. The most recent releases landed on September 3, 2026 and September 19, 2026 respectively.

Scorecard7 real differences · 3 level
Rhythm SYNC. versus Spren Body Composition Scanner: the parameters behind the verdict, then further details
ParameterRhythm SYNC.Spren Body Composition Scanner
PriceFreeFree
Rating1.8 (128 ratings)4.7 (1.5K ratings) — better
Positive reviews13.1% of reviews46.5% of reviews — better
Number of ratings1281.5K — better
Update frequencyEvery 3 monthsEvery 9 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPod — betteriPhone
Requires iOS12.0 — better17
Further details — not scored
Size47 MB207 MB
Age rating4+17+
DeveloperScoscheElite HRV Inc

Customer experience

Rhythm SYNC.

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

Spren Body Composition Scanner

All ratings1,486 ratings
Positive94.5%
Neutral1.5%
Negative4.0%
Written reviews99 reviews
Positive46.5%
Neutral5.1%
Negative48.5%

User reviews

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

Spren Body Composition Scanner

From 1.5K App Store ratings

What we love

  • 👍 Easy to operate
  • 🚀 Motivating
  • 👍 Incredible app
  • 👍 Accurate
  • 👍 Talks you through the scan

Room to improve

  • 🐛 No login possible
  • 🐛 Doesn't work
  • 🐛 Measurements are nowhere close to DEXA scans
  • 🐛 Can't delete account
  • 🐛 Useless

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

Spren Body Composition Scanner

Reported bugs

11 issues
  • No login possible
  • Doesn't work
  • Measurements are nowhere close to DEXA scans
  • Can't delete account
  • Useless
Show 6 more
  • Gimmicky at best
  • Impossible to get a reading since last update
  • App crashes when trying to set weight above 245lbs
  • Buggy
  • Bad image recognition
  • Doesn't scan under any circumstances

Requested features

3 requests
  • Integration with Apple Health for weight tracking
  • Demo or trial before subscription
  • Monthly subscription option

In-app purchases

None

Rhythm SYNC.

No in-app purchases

14 purchases

Spren Body Composition Scanner

Subscriptions11
  • Scan Essentials$10.491 Month
  • Monthly$14.991 Month
  • Monthly$19.991 Month
Show 8 more
  • 24/7 AI coaching support$20.991 Month
  • Monthly$24.991 Month
  • Scan Essentials$38.991 Year
  • Quarterly7 Days trial$59.993 Months
  • Annual$69.991 Year
  • Semiannual$89.996 Months
  • Annual7 Days trial$119.991 Year
  • 24/7 AI coaching support$129.001 Year
One-time3
  • Body Composition Analysis$8.99
  • Body Composition Analysis$17.99
  • Body Composition Analysis$35.99

Questions

Is Rhythm SYNC. free?
Rhythm SYNC. is free to download, with no in-app purchases.
Is Spren Body Composition Scanner free?
Spren Body Composition Scanner is free to download, with in-app purchases available.
Which has better reviews, Rhythm SYNC. or Spren Body Composition Scanner?
Spren Body Composition Scanner is rated higher. Rhythm SYNC. averages 1.8 out of 5 from 128 ratings, while Spren Body Composition Scanner averages 4.7 from 1.5K ratings.
Do Rhythm SYNC. or Spren Body Composition Scanner have ads?
Neither Rhythm SYNC. nor Spren Body Composition Scanner shows ads.
Which is updated more often, Rhythm SYNC. or Spren Body Composition Scanner?
Rhythm SYNC. ships an update every 3 months, and Spren Body Composition Scanner every 9 days. Most recently, Rhythm SYNC. was updated on September 3, 2026 and Spren Body Composition Scanner on September 19, 2026.

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