Comparison

Flex AI Workout Trainer & Log vs TRNR

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

Head to head
About

Flex AI Workout Trainer & Log

This app uses AI to provide personalized workout plans and real-time form feedback for weightlifters. It tracks progress, offers adaptive progression, and includes motivational features like leaderboards and streaks. It's designed for all experience levels, from beginners to pros.

Highlights
  • AI personal trainer
  • Real-time form feedback
  • Personalized workout plans
  • Adaptive progression
  • Strength tracking
  • Community leaderboards
  • Apple Watch integration
Features
Read full description

Flex AI is the world’s first true AI personal trainer — built for lifters who want to train smarter, progress faster, and perfect their form. Whether you’re chasing size, strength, or consistency, Flex uses real-time AI to guide every rep, adjust your program, and keep you motivated through challenges, leaderboards, and streaks. - Your AI Coach, Every Rep Personalized workouts built automatically by AI personas that learn your goals, history, and preferences. Real-time form feedback powered by patented computer-vision AI — get instant corrections on squats, bench, deadlift, rows, and more. Adaptive progression and deloading backed by sports-science principles — no spreadsheets, no guesswork. - Train Smarter — See Results AI tracks your strength curve and increases weight when you’re ready. Visual progress graphs show PRs, volume, and recovery trends. Track sets, reps, and tempo with a tap — or automatically with Apple Watch. - Stay Motivated & Connected Join a global community of lifters. Compete on leaderboards, build streaks, and earn badges. Post progress photos, celebrate milestones, and share results. - Accessible to Everyone Free to start with all core features included. Upgrade anytime for advanced AI coaching and premium analytics. Designed for all experience levels — from beginners to pros. - Why Flex AI Real-time AI form feedback (patented) Adaptive, science-based programming Progress tracking & recovery insights Gamified streaks + leaderboards Apple Watch integration Built for hypertrophy & strength goals Start Training Smarter — Today Download Flex AI and experience personal training powered by real AI. Perfect your form. Unlock your best lift. Train smarter — free on iPhone + Apple Watch.

About

TRNR

Access a wide range of high-quality workout guides with video and image demonstrations. Whether you're a beginner or an experienced athlete, find the equipment and guidance to achieve your fitness goals and maintain a healthy lifestyle. Save your favorite workouts for easy access anytime.

Highlights
  • High-quality workout guides
  • Video and image demonstrations
  • Equipment and guidance for all levels
  • Save and bookmark favorite workouts
  • Achieve fitness goals
  • Stay healthy
Features
Read full description

Welcome to our app! We are proud to offer a wide selection of high-quality workout guides that will help you reach your fitness goals. Our app features video and image guides of our various products , so you can get a feel for how they work and how to use them properly. Whether you're a beginner looking to start a fitness journey or a seasoned athlete looking to up your game, we've got the equipment and guides you need. We've got everything you need to get fit and stay healthy. In addition to our guides, you can save or bookmark your favorite workouts and go through them whenever you want. So why wait? Download our app and start building the body you've always wanted today!

Screenshots

Flex AI Workout Trainer & Log4 screens
TRNR4 screens

Verdict

The call

The clearest difference is in-app purchases: TRNR at none against Flex AI Workout Trainer & Log's 8. TRNR also leads on review sentiment (100% vs 69%) and iOS requirement (13.0 vs 18.0). On price, update cadence, 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. Flex AI Workout Trainer & Log sells 8 in-app purchases, starting at $12.99 per month. TRNR asks for nothing beyond the download.

UpkeepUpdate frequency

Flex AI Workout Trainer & Log ships an update every 9 days, TRNR every 10 days. The most recent releases landed on October 14, 2026 and September 27, 2026 respectively.

Scorecard4 real differences · 6 level
Flex AI Workout Trainer & Log versus TRNR: the parameters behind the verdict, then further details
ParameterFlex AI Workout Trainer & LogTRNR
PriceFreeFree
Rating4.6 (2.4K ratings) — better—
Positive reviews69.0% of reviews100.0% of reviews — better
Number of ratings2.4K — better—
Update frequencyEvery 9 days — betterEvery 10 days
AdsNoNo
In-app purchasesYesNo — better
MonetizationFreemiumFree — better
DevicesiPhone, Apple WatchiPhone, iPad, iPod — better
Requires iOS18.013.0 — better
Further details — not scored
Size574 MB22 MB
Age rating17+17+
DeveloperFlex Artificial Intelligence Inc.TRNR

Customer experience

Flex AI Workout Trainer & Log

All ratings2,409 ratings
Positive91.9%
Neutral2.6%
Negative5.4%
Written reviews310 reviews
Positive69.0%
Neutral6.5%
Negative24.5%

TRNR

Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Flex AI Workout Trainer & Log

Reported bugs

3 issues
  • App crashes on iOS 16 update
  • Inability to log workouts on previous days
  • Inconsistent syncing between app and Apple Watch

Requested features

4 requests
  • Offline workout mode
  • Ability to save and reuse custom workout plans
  • Muscle group targeting and analytics
  • Social features and community integration

TRNR

Not enough reviews yet to summarise bugs or requests.

In-app purchases

8 purchases

Flex AI Workout Trainer & Log

Subscriptions6
  • Premium Subscription Monthly$12.991 Month
  • Premium Plus Monthly$29.991 Month
  • Premium Plus Family Monthly$69.991 Month
Show 3 more
  • Premium Yearly Subscription$79.991 Year
  • Premium Plus Yearly7 Days trial$191.991 Year
  • Premium Plus Family Yearly7 Days trial$499.991 Year
One-time2
  • 1 Month Free PremiumFree
  • Lifetime Free PremiumFree
None

TRNR

No in-app purchases

Questions

Is Flex AI Workout Trainer & Log free?
Flex AI Workout Trainer & Log is free to download, with in-app purchases available.
Is TRNR free?
TRNR is free to download, with no in-app purchases.
Do Flex AI Workout Trainer & Log or TRNR have ads?
Neither Flex AI Workout Trainer & Log nor TRNR shows ads.
Which is updated more often, Flex AI Workout Trainer & Log or TRNR?
Flex AI Workout Trainer & Log ships an update every 9 days, and TRNR every 10 days. Most recently, Flex AI Workout Trainer & Log was updated on October 14, 2026 and TRNR on September 27, 2026.

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