# Flex AI Workout Trainer & Log — Fitness Tracker & Gym Planner

> AI-powered personal trainer for weightlifters, focusing on form, progression, and motivation. (iPhone/iPad app by Flex Artificial Intelligence Inc..)

- Source: https://appshunter.io/ios/app/flex-ai-workout-trainer-and-log/id1446354547 (this page in markdown: same URL + `.md`)
- Developer: [Flex Artificial Intelligence Inc.](https://appshunter.io/developer/1446354546)
- Category: Health & Fitness, Sports
- Price: Free with in-app purchases
- Rating: 4.60/5 from 2,405 App Store ratings · 303 written reviews indexed
- Age rating: 17+
- Requires: iOS 18.0 · 574 MB
- Languages: American English, Dutch, French (France), German (Germany), Hindi, Italian, Japanese, Korean, European Portuguese, Russian and 3 more
- Released: 2021-12-14
- Data updated: 2026-08-22
- Monetization: freemium
- User reviews in markdown: https://appshunter.io/ios/app/flex-ai-workout-trainer-and-log/id1446354547/reviews.md

## What is Flex AI Workout Trainer & Log?

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.

## Key features

- AI personal trainer
- Real-time form feedback
- Personalized workout plans
- Adaptive progression
- Strength tracking
- Community leaderboards
- Apple Watch integration

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Premium Subscription Monthly | $1.99 | per month |
| Premium Yearly Subscription | $9.99 | per year |
| Premium Plus Monthly | $2.99 | per month |
| Premium Plus Family Yearly | $49.99 | per year |
| Premium Plus Yearly | $19.99 | per year |
| Premium Plus Family Monthly | $9.99 | per month |

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| 1 Month Free Premium | Free | one-time |
| Lifetime Free Premium | Free | one-time |


## What do users think of Flex AI Workout Trainer & Log?

Overall sentiment: positive

**Pros**

- 🚀 Detailed workout tracking
- 👍 Customizable workouts
- 🔒 Comprehensive exercise library
- 💡 Helpful progress tracking
- 👍 Clean and intuitive interface
- 🚀 Seamless Apple Watch integration

**Cons**

- 🐛 Glitches and bugs
- 💰 Expensive premium subscription
- 🔒 Limited functionality without premium
- 🐛 Inconsistent rest timer
- 🐛 Workout data loss

**Commonly reported bugs**

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

**Most requested features**

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

## Recent user reviews (10 of 303)

All indexed reviews: https://appshunter.io/ios/app/flex-ai-workout-trainer-and-log/id1446354547/reviews.md

### 1/5 — Signing up

*2026-08-17, version 3.1*

This seems like a really good app but when I try to sign up for free I get stuck on the Progression overload is key to improve screen. If someone can help me that would mean a lot

### 1/5 — Rubbish

*2026-08-10, version 3.1*

I downloaded the app a few days ago and each time it freezes upon trying to set it up. Can’t be bothered anymore

### 1/5 — Love the app but they deleted my account and there is no tech support

*2026-08-07, version 3.1*

I’ve been using the app for years and enjoyed it. However I have been locked out of my account for weeks and trying to get in touch with their support department for and they have not responded. Very disappointing. Due to the lack of tech support, I do not recommend this app

### 5/5 — I love it

*2026-08-07, version 3.1*

This app helps me stay on track and increase weight and helps me stay organized!

### 5/5 — Consistency is key.

*2026-08-04, version 3.1*

Just recently getting back into my health journey and Flex AI has really helped me stay motivated and consistent.

### 1/5 — Doesn’t work

*2026-08-02, version 3.1*

I’ve been trying to use this app for the past two weeks. It doesn’t allow me to go beyond the tutorial.

### 5/5 — Solid app

*2026-08-01, version 3.1*

I’ve been using Flex for over a year and honestly has been one of the main reasons why I’ve made so much progress so quickly. Being able to track how often you lift, how much, and how long has really helped me a lot. App is especially good if you struggle with consistency, and I’ve seen other fitness trackers come out recently, but this one got it down for sure. Beats tracking lifts in the notes app 110%.

### 1/5 — Doesn’t Work

*2026-07-29, version 3.1*

Can’t even use the app. Freezes on the orientation process.

### 5/5 — Good

*2026-07-14, version 3.1*

Sometimes clunky, but way to keep track

### 1/5 — No response

*2026-06-29, version 3.1*

Not working or responding to support requests

## Frequently asked questions about Flex AI Workout Trainer & Log

### What does Flex AI Workout Trainer & Log do?

This app acts as an AI personal trainer for weightlifters. It provides personalized workout plans, real-time feedback on exercise form using computer vision, and adaptive progression based on sports science principles. It also includes features to track progress, stay motivated, and connect with a community.

### What are the key features of this fitness app?

Key features include an AI coach that generates personalized workouts, patented real-time form feedback for exercises like squats and deadlifts, adaptive progression and deloading, strength curve tracking, visual progress graphs, and integration with Apple Watch. It also offers gamified elements like leaderboards and streaks.

### How much does Flex AI Workout Trainer & Log cost?

The app is free to start, with all core features included. Users can upgrade at any time for advanced AI coaching and premium analytics. This freemium model allows access to essential training tools without an initial cost.

### What devices is this workout app compatible with?

The app is designed for iPhone and Apple Watch. It leverages Apple Watch for automatic tracking of sets, reps, and tempo, enhancing the user experience for those who use Apple's wearable technology.

### Who is this app designed for?

This app is built for lifters of all experience levels, from beginners to professionals. It's particularly beneficial for those focused on hypertrophy (muscle growth) and strength goals who want to train smarter, progress faster, and perfect their lifting technique.

## Version history (last 5 releases)

### 3.1 — 2026-04-09

• New design: Flex now has a revamped interface with a modern look and improved usability.
• Smarter AI trainer: Lex now creates and progresses your workouts with even more precision and intelligence.
• Performance improvements and bug fixes.

### 3.0.12 — 2026-03-16

Bug fixes and enhancements

### 3.0.11 — 2026-03-11

Bug fixes and enhancements

### 3.0.10 — 2026-03-05

Bug fixes and enhancements

### 3.0.9 — 2026-03-02

Bug fixes and enhancements

## Apps similar to Flex AI Workout Trainer & Log

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Fitbod: Gym & Fitness Planner](https://appshunter.io/ios/app/fitbod-gym-and-fitness-planner/id1041517543) | 4.8 (281,188) | Free | Health & Fitness |
| [Fitness AI Gym Workout Planner](https://appshunter.io/ios/app/fitness-ai-gym-workout-planner/id1446224156) | 4.7 (55,840) | Free | Health & Fitness |
| [Strong Workout Tracker Gym Log](https://appshunter.io/ios/app/strong-workout-tracker-gym-log/id464254577) | 4.9 (108,483) | Free | Health & Fitness |
| [Muscle Booster Workout Tracker](https://appshunter.io/ios/app/muscle-booster-workout-tracker/id1446447749) | 4.5 (136,878) | Free | Health & Fitness |
| [Gymverse: Gym Workout Planner](https://appshunter.io/ios/app/gymverse-gym-workout-planner/id1048454034) | 4.8 (164,766) | Free | Health & Fitness |
| [Hevy - Workout Tracker Gym Log](https://appshunter.io/ios/app/hevy-workout-tracker-gym-log/id1458862350) | 4.9 (87,295) | Free | Health & Fitness |

## Related topics

[artificial intelligence fitness](https://appshunter.io/ios/topics/artificial-intelligence-fitness) · [flex fitness and workout](https://appshunter.io/ios/topics/flex-fitness-and-workout) · [flex fitness training](https://appshunter.io/ios/topics/flex-fitness-training) · [arena energy tracker](https://appshunter.io/ios/topics/arena-energy-tracker) · [gibbon balance app](https://appshunter.io/ios/topics/gibbon-balance-app) · [oymotion gforce user app](https://appshunter.io/ios/topics/oymotion-gforce-user-app) · [foractive](https://appshunter.io/ios/topics/foractive) · [elite gym blackrock](https://appshunter.io/ios/topics/elite-gym-blackrock) · [rebound ai physio rehab coach](https://appshunter.io/ios/topics/rebound-ai-physio-rehab-coach) · [otfit ai](https://appshunter.io/ios/topics/otfit-ai) · [flex fitness](https://appshunter.io/ios/topics/flex-fitness) · [flex fitness woodland](https://appshunter.io/ios/topics/flex-fitness-woodland) · [grip fitness empire](https://appshunter.io/ios/topics/grip-fitness-empire) · [fitcore ai](https://appshunter.io/ios/topics/fitcore-ai) · [flexapp leudal](https://appshunter.io/ios/topics/flexapp-leudal) · [superior athlete ai](https://appshunter.io/ios/topics/superior-athlete-ai) · [tony moses fitness](https://appshunter.io/ios/topics/tony-moses-fitness) · [blaze ai workout tracker](https://appshunter.io/ios/topics/blaze-ai-workout-tracker) · [mkx coaching](https://appshunter.io/ios/topics/mkx-coaching) · [evolve fitness ridgewood](https://appshunter.io/ios/topics/evolve-fitness-ridgewood)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-22.*