# Flex AI Workout Trainer & Log vs Onyx Coach

The clearest difference is review sentiment: Onyx Coach at 100% against Flex AI Workout Trainer & Log's 69%. Onyx Coach also leads on rating (5.0 vs 4.6) and iOS requirement (16.4 vs 18.0). Flex AI Workout Trainer & Log's advantage is ratings volume (2.4K vs 2). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Flex AI Workout Trainer & Log sells 8 in-app purchases, starting at $12.99 per month and Onyx Coach sells 6 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.

Onyx Coach holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Flex AI Workout Trainer & Log has 2.4K ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 69% of Flex AI Workout Trainer & Log's written reviews are positive against 100% of Onyx Coach's.

Both ship on a similar rhythm, roughly every 9 days. The most recent releases landed on October 20, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | Flex AI Workout Trainer & Log | Onyx Coach |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (2.4K ratings)](https://appshunter.io/ios/app/flex-ai-workout-trainer-and-log/id1446354547/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/onyx-coach-workout-tracker/id6737855506/reviews)** |
| Number of ratings | **2.4K** | 2 |
| Positive reviews | 69.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 9 days | Every 9 days |
| Monetization | Freemium | Free with in-app purchases |
| Size | 574 MB | 148 MB |
| Requires iOS | 18.0 | **16.4** |
| Devices | **iPhone, Apple Watch** | iPhone |
| Age rating | 17+ | 4+ |
| Developer | [Flex Artificial Intelligence Inc.](https://appshunter.io/developer/1446354546) | [Coachito LLC](https://appshunter.io/developer/1873867082) |

## What reviewers say

### Flex AI Workout Trainer & Log

[App page](https://appshunter.io/ios/app/flex-ai-workout-trainer-and-log/id1446354547)

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:** Family Sharing, Apple Watch app, Vision Pro support

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Subscription Monthly | $12.99 | per month |
| Premium Plus Monthly | $29.99 | per month |
| Premium Plus Family Monthly | $69.99 | per month |
| Premium Yearly Subscription | $79.99 | per year |
| Premium Plus Yearly | $191.99 | per year |
| Premium Plus Family Yearly | $499.99 | per year |
| 1 Month Free Premium | Free | one-time |
| Lifetime Free Premium | Free | one-time |

**What reviewers like**

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

**What reviewers complain about**

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

**Reported bugs**

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

**Requested features**

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


### Onyx Coach

[App page](https://appshunter.io/ios/app/onyx-coach-workout-tracker/id6737855506)

This app helps you plan and track your strength training workouts with pre-built programs and a fast logging system. It's designed to help you master progressive overload and visualize your gains, replacing paper journals and spreadsheets.

**Highlights:** Pre-built gym routines, Custom workout builder, Fast workout logging, Progressive overload tracking, Rest timer, Plate calculator

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Onyx Coach Premium (Monthly) | $9.99 | per month |
| Onyx Coach Premium (Monthly) | $9.99 | per month |
| Premium Monthly | $9.99 | per month |
| Onyx Coach Premium (Six months) | $64.99 | per 6 months |
| Onyx Coach Premium (Yearly) | $79.00 | per year |
| Premium Yearly | $79.00 | per year |


## Frequently asked questions

### Is Flex AI Workout Trainer & Log free?

Flex AI Workout Trainer & Log is free to download, with in-app purchases available.

### Is Onyx Coach free?

Onyx Coach is free to download, with in-app purchases available.

### Which has better reviews, Flex AI Workout Trainer & Log or Onyx Coach?

Onyx Coach is rated higher. Flex AI Workout Trainer & Log averages 4.6 out of 5 from 2.4K ratings, while Onyx Coach averages 5.0 from 2 ratings.

### Do Flex AI Workout Trainer & Log or Onyx Coach have ads?

Neither Flex AI Workout Trainer & Log nor Onyx Coach shows ads.

### Which is updated more often, Flex AI Workout Trainer & Log or Onyx Coach?

Flex AI Workout Trainer & Log ships an update every 9 days, and Onyx Coach every 9 days. Most recently, Flex AI Workout Trainer & Log was updated on October 20, 2026 and Onyx Coach on October 2, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*