Comparison

Polar Flow vs The SIX

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

The SIX

Features
Read full description

The SIX is the new way to rate your fitness. Built in collaboration with Gymshark, The SIX gives you a single performance rating across key pillars of fitness so you can finally show how good you really are in the gym. No guessing. No ego. No noise. Just your data, your effort, your proof. What you can do inside The SIX: * Complete structured fitness tests that cover strength, power, speed, capacity, endurance, and conditioning * Get your personal SIX rating based on your results * Track your progress over time as your rating increases * Create head to head comparisons with friends to see who wins, loses, or ties across each of The SIX * Record in-app video of your attempts so others can watch your lifts and efforts * Learn correct technique from Gymshark Lifting Club coaches with built-in movement guides and videos * Share achievement stickers and rating cards straight to Instagram and other social channels for social proof * Build social currency around your effort, not just your appearance * Compete on leaderboards and see where you stand The SIX creates a democratised rating for fitness. It gives every lifter and gym goer one clear number that reflects real performance, not opinion. Your training already matters. Now it counts. What is your SIX?

Screenshots

Polar Flow4 screens
The SIX4 screens

Verdict

The call

The clearest difference is in-app purchases: The SIX at none against Polar Flow's 1. The SIX also leads on update cadence (weekly vs monthly) and iOS requirement (15.6 vs 17.0). 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. Polar Flow sells 1 in-app purchase, starting at $8.99 per month. The SIX asks for nothing beyond the download.

UpkeepUpdate frequency

Polar Flow ships an update monthly, The SIX weekly. The most recent releases landed on November 6, 2026 and November 5, 2026 respectively.

Scorecard3 real differences · 7 level
Polar Flow versus The SIX: the parameters behind the verdict, then further details
ParameterPolar FlowThe SIX
PriceFreeFree
Rating4.6 (50K ratings) — better—
Positive reviews49.6% of reviews—
Number of ratings50K — better—
Update frequencyMonthlyWeekly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.015.6 — better
Further details — not scored
Size189 MB99 MB
Age rating4+17+
DeveloperPolar ElectroArchon Combine Limited

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

The SIX

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

The SIX

No in-app purchases

Questions

Is Polar Flow free?
Polar Flow is free to download, with in-app purchases available.
Is The SIX free?
The SIX is free to download, with no in-app purchases.
Do Polar Flow or The SIX have ads?
Neither Polar Flow nor The SIX shows ads.
Which is updated more often, Polar Flow or The SIX?
Polar Flow ships an update monthly, and The SIX weekly. Most recently, Polar Flow was updated on November 6, 2026 and The SIX on November 5, 2026.

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