# nitroxCalc vs Scuba Dive Signals

The clearest difference is update cadence: nitroxCalc at every 18 months against Scuba Dive Signals's every 42 months. nitroxCalc also leads on iOS requirement (9.0 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

nitroxCalc ships an update every 18 months, Scuba Dive Signals every 42 months. The most recent releases landed on October 11, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | nitroxCalc | Scuba Dive Signals |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (3 ratings)](https://appshunter.io/ios/app/scuba-dive-signals/id1483856571/reviews)** |
| Number of ratings | — | **3** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 18 months** | Every 42 months |
| Monetization | — | Free |
| Size | 5 MB | 3 MB |
| Requires iOS | **9.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [CAP-REL](https://appshunter.io/developer/1405536766) | [Eric Hamiter](https://appshunter.io/developer/1482332471) |

## What reviewers say

### nitroxCalc

[App page](https://appshunter.io/ios/app/nitroxcalc/id1408060704)

**Features:** macOS Compatibility

**In-app purchases:** none


### Scuba Dive Signals

[App page](https://appshunter.io/ios/app/scuba-dive-signals/id1483856571)

Access a comprehensive list of underwater hand signals for safe scuba diving communication. Includes a quiz feature to test your knowledge of signals recognized by major training agencies.

**Highlights:** List of recognized dive hand signals, Signals from PADI, NAUI, SSI, Quiz feature to test knowledge, Safety communication focus, Creative Commons licensed images

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is nitroxCalc free?

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

### Is Scuba Dive Signals free?

Scuba Dive Signals is free to download, with no in-app purchases.

### Do nitroxCalc or Scuba Dive Signals have ads?

Neither nitroxCalc nor Scuba Dive Signals shows ads.

### Which is updated more often, nitroxCalc or Scuba Dive Signals?

nitroxCalc ships an update every 18 months, and Scuba Dive Signals every 42 months. Most recently, nitroxCalc was updated on October 11, 2026 and Scuba Dive Signals on October 8, 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.*