Comparison

Polar Flow vs ImersU

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

Head to head
About

Polar Flow

This app helps you track daily activity, analyze workouts with detailed metrics, and gain insights into sleep patterns and recovery. It allows for device management, route planning, and seamless syncing with other popular fitness platforms.

Highlights
  • Activity Tracking
  • Training Analysis
  • Sleep Insights
  • Training Load & Recovery
  • Device & Profile Management
  • Wireless Syncing
  • Third-Party Service Integration
Features
Read full description

Polar Flow: Your Personal Sports, Fitness, and Health Companion The exclusive app designed to maximize the potential of your Polar devices. Key Features: Activity Tracking: Monitor your daily activity, steps, calories burned, and distance to stay motivated throughout the day. Training Analysis: Dive deep into your workouts with detailed data on heart rate, speed, pace, distance, power, and more. Understand the impact of each session and optimize your training routines. Sleep Insights: Discover how well you sleep with advanced sleep tracking. Get feedback on sleep stages and quality to improve your rest and recovery. See how sleep boosts your day and track skin temperature changes. Training Load & Recovery: Understand how your training sessions strain your body and get recommendations on recovery time to prevent overtraining. Manage your watch and profile: Customize and manage your Polar device, Sports profiles for different activities, Routes, and Training Targets. Wireless Syncing: Automatically sync data from your Polar devices for real-time updates, notifications, and other insights. Stay Connected: Connect your profile and sync your data with Strava, TrainingPeaks, Adidas, komoot, and many other services. Why Choose Polar Flow? Personalized Guidance: Receive personalized feedback and guidance and understand your progress. Comprehensive Ecosystem: Integrates seamlessly with Polar watches, heart rate monitors, and more for a holistic experience. User-Friendly Interface: Navigate your data effortlessly with our intuitive and clean design. Notification support: Your Polar watch will receive the same notifications as your phone screen—incoming calls, messages, and app notifications. Secure and Private: Your data is safely stored and protected, giving you peace of mind as you focus on your journey. Polar Flow app allows you to share some of your wellness data with Apple Health. This includes details of your training, your heart rate, and steps. Please note Polar Flow app is not intended for medical or diagnostic use. Get Started Today! Download Polar Flow and unlock the full potential of your Polar devices. You can find more info at https://www.polar.com/flow Connect with us! Instagram: www.instagram.com/polarglobal Facebook: www.facebook.com/polarglobal YouTube: www.youtube.com/polarglobal Find out more about Polar products at https://www.polar.com/en/products

About

ImersU

Experience indoor rowing like never before with virtual, real-world courses. Train or race against AI, customize your environment, and connect with your rowing machine for an immersive fitness journey.

Highlights
  • Virtual real-world rowing courses
  • Customizable time of day and weather
  • AI boat racing
  • Connects with rowing machines via Bluetooth FTMS
  • Flow Row mode for non-connected ergometers
  • Multi-screen display support
Read full description

ImersU ROW helps make indoor rowing more enjoyable and rewarding by bringing the outdoors indoors. Row virtually on stunning, real-world courses, select time of day, weather, and viewing perspective. Train or Race against AI boats, challenge yourself, or take yourself out for a paddle. Pair with your ergo for a connected row or simply choose your speed and get into the flow so you can enjoy mersU on every rowing ergo. Rowing is the most efficient form of training compared to running and cycling, with over 86% of muscle groups being used. Many people have shied away from indoor rowing as it was considered boring. But no more. Combine the most efficient form of indoor training with stunning content, game play, and a growing community, and rowing is becoming the go-to choice for indoor training. Join the growing number of people making indoor rowing a central part of their fitness regime. With imersU, you can row in multiple locations, including Tokyo, Paris, Henley, and The Tideway. Turn your home rowing machine or gym session into a journey shared by elite athletes. imersU uses standard Bluetooth FTMS protocol so you can connect to compatible devices; these include Concept 2 PM5 and the WaterRower S4. There is also a Companion App, should you wish to connect on Windows and race against up to 7 other competitors when in the same room. The imersU content has been created to be displayed on all the latest phones and tablets as well as on high-powered MACS and PCs, so you can choose how you experience imersU ROW. At its most immersive, imersU can be displayed on super-sized screens on 3 walls to give you that on-water experience of having other rowers ‘on your shoulder. The app comes with NDI screen settings for connection to multiple monitors to make this possible. For the first time, you can join a rowing community whilst creating a rowing environment that suits your needs. An equivalent of a Maybach to an A-Class. Some users may not have the latest ergo that can connect to the imersU app, but they still want to be able to row on iconic courses. imersU has FLOW ROW, a feature that lets the user set a split time and then row in FLOW with the course environment as the ergo speed is matched to the selected split time. imersU will turn every training session into an experience that will keep you motivated and engaged to help you become fitter and stronger. WHY CHOOSE imersU ROW: • Stunning graphics created in Unreal Engine 5, an industry pioneer in creating virtual environments, are designed to inspire you as if you were in the great outdoors, but where you control the weather. • The ability to connect to multiple screens to create an indoor rowing environment that can be fully immersive and extensive, as you choose, or simply enjoyed on a tablet. • Use the benefits of virtual environments to add in AI boats to race against and help you focus on your goals. • Choose your time of day, weather, and viewing perspective, and track how your performance can be affected by your environment. • Enjoy imersU on every single rowing ergo with the FLOW ROW feature as well as enjoy connected rowing on leading Bluetooth-enabled ergos. SUPPORTING THE COMMUNITY imersU believes in the benefits that rowing can bring to the community. As a result, imersU has special rates and arrangements with all those under 15, schools and rowing clubs to enable as many people as possible to experience rowing in the places rowed by the elite rowers. For everyone else, imersU can be enjoyed in an unlimited way each month for £14.99, with some prices affected by currency. Your involvement in imersU will help those new to rowing enjoy the benefits indoor rowing brings. Please see Terms of Use at https://row.imersu.com/register

Screenshots

Polar Flow4 screens
ImersU4 screens

Verdict

The call

The clearest difference is rating: Polar Flow at 4.6 against ImersU's 3.0. Polar Flow also leads on ratings volume (50K vs 2). ImersU's advantage is in-app purchases (none vs 1) and review sentiment (60% vs 50%). On price, update cadence 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Polar Flow sells 1 in-app purchase, starting at $8.99 per month. ImersU asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Polar Flow holds the better App Store score, 4.6 against 3.0. That said, the two scores are not equally well evidenced: Polar Flow has 50K ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 50% of Polar Flow's written reviews are positive against 60% of ImersU's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Polar Flow ships an update monthly, ImersU every 2 weeks. The most recent releases landed on September 24, 2026 and September 10, 2026 respectively.

Scorecard7 real differences · 3 level
Polar Flow versus ImersU: the parameters behind the verdict, then further details
ParameterPolar FlowImersU
PriceFreeFree
Rating4.6 (50K ratings) — better3.0 (2 ratings)
Positive reviews49.6% of reviews60.0% of reviews — better
Number of ratings50K — better2
Update frequencyMonthlyEvery 2 weeks — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPadiPhone, iPad, iPod, Mac — better
Requires iOS17.015.0 — better
Further details — not scored
Size188 MB259 MB
Age rating4+4+
DeveloperPolar ElectroImmersive Gym Company Limited

Customer experience

Polar Flow

All ratings49,868 ratings
Positive91.3%
Neutral4.5%
Negative4.2%
Written reviews2,171 reviews
Positive49.6%
Neutral11.3%
Negative39.1%

ImersU

All ratings2 ratings
Positive0.0%
Neutral100.0%
Negative0.0%
Written reviews5 reviews
Positive60.0%
Neutral40.0%
Negative0.0%

Bugs and requests

Polar Flow

Reported bugs

3 issues
  • App crashes during syncing
  • Inconsistent data sync between watch and app
  • Firmware updates causing loss of user data

Requested features

4 requests
  • Ability to manually edit workout data
  • Integration with more third-party apps
  • More advanced training programs and coaching
  • Improved sleep tracking and analysis

ImersU

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Polar Flow

Subscriptions1
  • Polar Fitness Program1 Month trial$8.991 Month
None

ImersU

No in-app purchases

Questions

Is Polar Flow free?
Polar Flow is free to download, with in-app purchases available.
Is ImersU free?
ImersU is free to download, with no in-app purchases.
Which has better reviews, Polar Flow or ImersU?
Polar Flow is rated higher. Polar Flow averages 4.6 out of 5 from 50K ratings, while ImersU averages 3.0 from 2 ratings.
Do Polar Flow or ImersU have ads?
Neither Polar Flow nor ImersU shows ads.
Which is updated more often, Polar Flow or ImersU?
Polar Flow ships an update monthly, and ImersU every 2 weeks. Most recently, Polar Flow was updated on September 24, 2026 and ImersU on September 10, 2026.

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