# Codex History vs ML_Engineering

The clearest difference is in-app purchases: Codex History at none against ML_Engineering's 1. ML_Engineering's advantage is device support. On price and iOS requirement there is nothing between them.

Both are free to download. ML_Engineering sells 1 in-app purchase, starting at $1.99 per month. Codex History asks for nothing beyond the download.

## The numbers

| Metric | Codex History | ML_Engineering |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | — | No |
| Update frequency | — | Every 3 weeks |
| Size | 1 MB | 5 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | — | **iPhone, iPad, Mac** |
| Age rating | 4+ | 4+ |
| Developer | [Jingling Zhu](https://appshunter.io/developer/1632188995) | [Luke Mclaughlin](https://appshunter.io/developer/1893671036) |

## What reviewers say

### Codex History

[App page](https://appshunter.io/ios/app/codex-history/id6760963039)

**In-app purchases:** none


### ML_Engineering

[App page](https://appshunter.io/ios/app/ml-engineering/id6789723889)

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| ML_Engineering Pro | $1.99 | per month |


## Frequently asked questions

### Is Codex History free?

Codex History is free to download, with no in-app purchases.

### Is ML_Engineering free?

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

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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.*