Comparison

FLEX Stronger vs Proteus Motion

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

Head to head
About

FLEX Stronger

This app revolutionizes weight training by syncing with a sensor to provide real-time performance feedback. Track, manage, and review your training like elite athletes, with automated workouts and group training options. It offers detailed metrics, video recording with data overlay, and a community feature for sharing and downloading workouts.

Highlights
  • Real-time performance feedback
  • Velocity-based training (VBT)
  • Automated workouts
  • Group training for up to three people
  • Video recording with synced data
  • 1RM prediction
  • Workout creation and sharing
Features
Read full description

Revolutionise the way you train and prepare in the weights room! The FLEX Stronger app syncs to a FLEX barbell sensor to deliver real-time feedback straight to your device. Track, manage and review training performance just like elite and professional athletes right across the globe, through the Major Leagues, UFC, Premier League and Olympic institutes. Developed by the team at GymAware, FLEX packages everything we learned from delivering gold standard products to the pro ranks into the only VBT system developed specifically for individual use. The smartest system on the market, FLEX automates your entire training experience. Select an exercise. Load some weight. Lift. Completely wireless. No calibration, adjustments or exercise creation required. Perfect for individual athletes, remote coaches and personal trainers. *Performance Metrics & Targets* Precise and immediate feedback on Mean and Peak Velocity, Mean and Peak Power, Distance, Height, Eccentrics, Position and live bar path tracing. Set targets on key performance metrics to benchmark effort across your session. *Group Training* Add other lifters into your session for group training with up to three people. Complete regular training, pre-programmed workouts or even the 1RM prediction with your group. Training partners who complete sessions with you can collect and store their data in their own profiles once the session is done. Training partners can be added or removed from sessions at any time. *Video Mode* Switch to video mode and record your set with synced data overlaid on the saved file. Send to friends, coaches or share online. Handsfree start and stop. Set your device up and lift. Your video will start, stop and crop to capture the set you just completed. *Automated Workouts* Complete workouts that step you through the entire program, from exercise and weight changes to targets and rest times. *Create, Share and Download Workouts* Create custom workouts directly in the app. Let FLEX run you through your new program, or share them via our Community feature with training partners or clients using FLEX. Looking for inspiration, download sessions from any of your connections in Community and complete them yourself. Set targets based on their results and compete and compare over the same workout. *1RM Predictions* Use the automated 1RM prediction protocol to gauge current strength and readiness levels without an actual 1RM attempt. *Multitasking* There are no limits in the FLEX app. Start regular sessions and add in training partners, or start a pre-programmed workout. Background the app and switch on your favourite tunes. Browse your historical results in the middle of your training sessions. Whatever you need is accessible any time. *Community* Create connections in the FLEX community so you can browse their training history, download sessions (complete with their results), send workouts, train in groups. View session data live as it is uploaded set by set, and interact with fist bumps and comments directly on the platform. *Store and Review* All your data is stored and reviewable in History right in your app. Data is securely backed upon our servers and retrieved on your device at any time.

About

Proteus Motion

This app provides advanced performance training and recovery analytics. It enables low-impact, high-efficiency 3D resistance training. A Proteus System user account is required to use the app.

Highlights
  • Performance training analytics
  • Recovery analytics
  • 3D resistance training
  • High efficiency training
  • Low-impact training
Features
Read full description

Proteus Motion is leading the reinvention of performance training and recovery. The Proteus System delivers breakthrough analytics and first-ever 3D resistance training for high efficiency, low-impact training. NOTE: This app requires an active user account with the Proteus System.

Screenshots

FLEX Stronger4 screens
Proteus Motion4 screens

Verdict

The call

The clearest difference is review sentiment: FLEX Stronger at 71% against Proteus Motion's 0%. FLEX Stronger also leads on rating (4.4 vs 3.0) and update cadence (monthly vs every 6 months). On price, ads, in-app purchases and monetization model 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

FLEX Stronger holds the better App Store score, 4.4 against 3.0. Both are backed by a comparable volume of ratings — 8 and 2 respectively. Written reviews point the same way: 71% of FLEX Stronger's written reviews are positive against 0% of Proteus Motion's.

UpkeepUpdate frequency

FLEX Stronger ships an update monthly, Proteus Motion every 6 months. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

Scorecard4 real differences · 6 level
FLEX Stronger versus Proteus Motion: the parameters behind the verdict, then further details
ParameterFLEX StrongerProteus Motion
PriceFreeFree
Rating4.4 (8 ratings) — better3.0 (2 ratings)
Positive reviews71.4% of reviews — better0.0% of reviews
Number of ratings8 — better2
Update frequencyMonthly — betterEvery 6 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.0 — better15.1
Further details — not scored
Size56 MB38 MB
Age rating17+4+
DeveloperKinetic PerformanceProteus Motion Inc.

Customer experience

FLEX Stronger

All ratings8 ratings
Positive87.5%
Neutral0.0%
Negative12.5%
Written reviews7 reviews
Positive71.4%
Neutral14.3%
Negative14.3%

Proteus Motion

All ratings2 ratings
Positive50.0%
Neutral0.0%
Negative50.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

FLEX Stronger

No in-app purchases

None

Proteus Motion

No in-app purchases

Questions

Is FLEX Stronger free?
FLEX Stronger is free to download, with no in-app purchases.
Is Proteus Motion free?
Proteus Motion is free to download, with no in-app purchases.
Which has better reviews, FLEX Stronger or Proteus Motion?
FLEX Stronger is rated higher. FLEX Stronger averages 4.4 out of 5 from 8 ratings, while Proteus Motion averages 3.0 from 2 ratings.
Do FLEX Stronger or Proteus Motion have ads?
Neither FLEX Stronger nor Proteus Motion shows ads.
Which is updated more often, FLEX Stronger or Proteus Motion?
FLEX Stronger ships an update monthly, and Proteus Motion every 6 months. Most recently, FLEX Stronger was updated on November 2, 2026 and Proteus Motion on November 3, 2026.

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