# Subsurface vs nitroxCalc

The clearest difference is update cadence: Subsurface at every 2 months against nitroxCalc's every 18 months. nitroxCalc's advantage is iOS requirement (9.0 vs 17). 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.

Subsurface ships an update every 2 months, nitroxCalc every 18 months. The most recent releases landed on September 18, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Subsurface | nitroxCalc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (48 ratings)](https://appshunter.io/ios/app/subsurface-mobile/id1093217161/reviews)** | — |
| Number of ratings | **48** | — |
| Positive reviews | 63.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 18 months |
| Monetization | Free | — |
| Size | 52 MB | 5 MB |
| Requires iOS | 17 | **9.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dirk Hohndel](https://appshunter.io/developer/1093217160) | [CAP-REL](https://appshunter.io/developer/1405536766) |

## What reviewers say

### Subsurface

[App page](https://appshunter.io/ios/app/subsurface-mobile/id1093217161)

This application allows divers to manage their dive logs on their mobile devices. It supports editing dive data and downloading new information from compatible dive computers. Optional cloud synchronization is available for seamless data transfer with desktop versions.

**Highlights:** Mobile dive log management, Edit dive data, Download from Bluetooth LE dive computers, Optional cloud synchronization, Open-source and free

**In-app purchases:** none


### nitroxCalc

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

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Subsurface free?

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

### Is nitroxCalc free?

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

### Do Subsurface or nitroxCalc have ads?

Neither Subsurface nor nitroxCalc shows ads.

### Which is updated more often, Subsurface or nitroxCalc?

Subsurface ships an update every 2 months, and nitroxCalc every 18 months. Most recently, Subsurface was updated on September 18, 2026 and nitroxCalc on September 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.*