# HydroCalc Plus vs NiuMa闹钟

The clearest difference is price: NiuMa闹钟 at Free against HydroCalc Plus's $3.99. NiuMa闹钟 also leads on update cadence (every 5 days vs every 3 weeks). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

NiuMa闹钟 is free to download; HydroCalc Plus costs $3.99 up front. HydroCalc Plus sells 4 one-off in-app purchases and NiuMa闹钟 sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

HydroCalc Plus ships an update every 3 weeks, NiuMa闹钟 every 5 days. The most recent releases landed on October 4, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | HydroCalc Plus | NiuMa闹钟 |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hydrocalc-plus/id578807688/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 5 days** |
| Monetization | Paid | — |
| Size | 34 MB | 15 MB |
| Requires iOS | **15.1** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 17+ |
| Developer | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) | [志文 李](https://appshunter.io/developer/1852909959) |

## What reviewers say

### HydroCalc Plus

[App page](https://appshunter.io/ios/app/hydrocalc-plus/id578807688)

A professional tool for hydraulic engineers to calculate pressure losses in piping systems. It supports US and SI units, offers an extensive pipe material and fittings database, and includes inverse calculations for design optimization.

**Highlights:** Friction head loss calculation (Hazen-Williams), US and SI unit support, Extensive pipe material library, Fittings and valves database, Inverse calculation mode, Real-time results (velocity, losses)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pump Power Calculator | $1.99 | one-time |
| System Curve Generator | $1.99 | one-time |
| Pipe Database | $1.99 | one-time |
| Industrial Fluids Pack | $2.99 | one-time |


### NiuMa闹钟

[App page](https://appshunter.io/ios/app/niuma/id6761598998)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro会员 | $2.99 | one-time |


## Frequently asked questions

### Is HydroCalc Plus free?

HydroCalc Plus costs $3.99, and also offers in-app purchases.

### Is NiuMa闹钟 free?

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

### Do HydroCalc Plus or NiuMa闹钟 have ads?

Neither HydroCalc Plus nor NiuMa闹钟 shows ads.

### Which is updated more often, HydroCalc Plus or NiuMa闹钟?

HydroCalc Plus ships an update every 3 weeks, and NiuMa闹钟 every 5 days. Most recently, HydroCalc Plus was updated on October 4, 2026 and NiuMa闹钟 on October 9, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*