# Nitrox by Envivia vs Curios Pro

The clearest difference is update cadence: Curios Pro at daily against Nitrox by Envivia's every 6 weeks. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Nitrox by Envivia sells 4 in-app purchases, starting at $9.99 per year and Curios Pro sells 2 in-app purchases, starting at $5.99 per month. Whichever you choose, the download price is not the number that matters.

Nitrox by Envivia ships an update every 6 weeks, Curios Pro daily. The most recent releases landed on August 29, 2026 and May 19, 2026 respectively.

## The numbers

| Metric | Nitrox by Envivia | Curios Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/nitrox-by-envivia/id1613770132/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Daily** |
| Monetization | Free with in-app purchases | — |
| Size | 72 MB | 40 MB |
| Requires iOS | 15.6 | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [ENVIVIA](https://appshunter.io/developer/1583628615) | [Djalae OUIS](https://appshunter.io/developer/1812210037) |

## What reviewers say

### Nitrox by Envivia

[App page](https://appshunter.io/ios/app/nitrox-by-envivia/id1613770132)

This app is a premium digital guide for Nitrox diving, offering educational content and calculation tools to optimize dives. It helps divers understand oxygen limits, plan dives using gradient factors, and prepare for certification.

**Highlights:** Calculate MOD (Maximum Operating Depth), Manage oxygen partial pressure (PPO₂), Optimize Nitrox dive planning, Understand oxygen-related physiological limits, Prepare for Nitrox certification, Multilingual support

**Features:** Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $9.99 | per year |
| Thank you | $1.99 | one-time |
| Popular | $9.99 | one-time |
| Generous | $49.99 | one-time |


### Curios Pro

[App page](https://appshunter.io/ios/app/curios-pro/id6745432047)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Curios Pro | $5.99 | per month |
| Curios Pro | $59.99 | per year |


## Frequently asked questions

### Is Nitrox by Envivia free?

Nitrox by Envivia is free to download, with in-app purchases available.

### Is Curios Pro free?

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

### Do Nitrox by Envivia or Curios Pro have ads?

Neither Nitrox by Envivia nor Curios Pro shows ads.

### Which is updated more often, Nitrox by Envivia or Curios Pro?

Nitrox by Envivia ships an update every 6 weeks, and Curios Pro daily. Most recently, Nitrox by Envivia was updated on August 29, 2026 and Curios Pro on May 19, 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.*