# adz vs HydroCalc

The clearest difference is in-app purchases: adz at none against HydroCalc's 1. adz also leads on iOS requirement (15.6 vs 17.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. HydroCalc sells 1 one-off in-app purchase. adz asks for nothing beyond the download.

adz ships an update every 4 months, HydroCalc every 2 months. The most recent releases landed on October 27, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | adz | HydroCalc |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Size | 20 MB | 1 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [arcade solutions ag](https://appshunter.io/developer/1105330983) | [Piotr Kaminski](https://appshunter.io/developer/6799375980) |

## What reviewers say

### adz

[App page](https://appshunter.io/ios/app/adz/id1634024819)

**Features:** Vision Pro support

**In-app purchases:** none


### HydroCalc

[App page](https://appshunter.io/ios/app/hydrocalc-heating-and-flow/id6801788464)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HydroCalc Pro | $3.99 | one-time |


## Frequently asked questions

### Is adz free?

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

### Is HydroCalc free?

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

### Do adz or HydroCalc have ads?

Neither adz nor HydroCalc shows ads.

### Which is updated more often, adz or HydroCalc?

adz ships an update every 4 months, and HydroCalc every 2 months. Most recently, adz was updated on October 27, 2026 and HydroCalc on October 25, 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.*