# Hydrology Formulator vs SoilHue

The clearest difference is rating: Hydrology Formulator at 5.0 against SoilHue's 1.0. SoilHue's advantage is in-app purchases (none vs 1) and update cadence (every 2 months vs every 6 months). On price, review sentiment, ratings volume and ads there is nothing between them.

Both are free to download. Hydrology Formulator sells 1 one-off in-app purchase. SoilHue asks for nothing beyond the download.

Hydrology Formulator holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively. Written reviews split almost evenly too, at 0% and 0% positive.

Hydrology Formulator ships an update every 6 months, SoilHue every 2 months. The most recent releases landed on October 8, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | Hydrology Formulator | SoilHue |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hydrology-formulator/id346512904/reviews)** | [1.0 (1 ratings)](https://appshunter.io/ios/app/soilhue/id6744872595/reviews) |
| Number of ratings | 1 | 1 |
| Positive reviews | 0.0% of reviews | 0.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 2 months** |
| Monetization | Free | Free |
| Size | 18 MB | 3 MB |
| Requires iOS | 18.6 | **17.6** |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Historycentral.com](https://appshunter.io/developer/1744330560) | [Antonio J. Gonzalez](https://appshunter.io/developer/667099261) |

## What reviewers say

### Hydrology Formulator

[App page](https://appshunter.io/ios/app/hydrology-formulator/id346512904)

This app provides a comprehensive collection of over 1,000 formulas, calculators, and conversions for hydrology and civil engineering. It covers a wide range of topics including groundwater, stormwater, pipe flow, and water pollution.

**Highlights:** 1,000+ formulas and calculators, Groundwater analysis tools, Stormwater design calculations, Open channel and pipe flow equations, Water pollution modeling, Conversions and reference data

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

**In-app purchases (1)**

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


### SoilHue

[App page](https://appshunter.io/ios/app/soilhue/id6744872595)

This app analyzes soil color from photographs, providing Munsell notation and an approximate USDA soil order. It offers advanced camera calibration and on-device processing for privacy. Ideal for professionals and students working with soil.

**Highlights:** Soil color identification from photos, Munsell notation and USDA soil order, Advanced camera calibration, On-device image analysis, Export data to .xlsx, Lighting condition check

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

**In-app purchases:** none


## Frequently asked questions

### Is Hydrology Formulator free?

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

### Is SoilHue free?

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

### Which has better reviews, Hydrology Formulator or SoilHue?

Hydrology Formulator is rated higher. Hydrology Formulator averages 5.0 out of 5 from 1 ratings, while SoilHue averages 1.0 from 1 ratings.

### Do Hydrology Formulator or SoilHue have ads?

Neither Hydrology Formulator nor SoilHue shows ads.

### Which is updated more often, Hydrology Formulator or SoilHue?

Hydrology Formulator ships an update every 6 months, and SoilHue every 2 months. Most recently, Hydrology Formulator was updated on October 8, 2026 and SoilHue on September 28, 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.*