# Hydrology Formulator vs Simplot Advisor

The clearest difference is rating: Hydrology Formulator at 5.0 against Simplot Advisor's 4.3. Simplot Advisor's advantage is in-app purchases (none vs 1) and update cadence (every 3 weeks vs every 6 months). On price, ads, monetization model and device support there is nothing between them.

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

Hydrology Formulator holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: Simplot Advisor has 6 ratings behind it against 1, so its average is the more settled of the two.

Hydrology Formulator ships an update every 6 months, Simplot Advisor every 3 weeks. Both last shipped on October 24, 2026.

## The numbers

| Metric | Hydrology Formulator | Simplot Advisor |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/hydrology-formulator/id346512904/reviews)** | [4.3 (6 ratings)](https://appshunter.io/ios/app/simplot-advisor/id1361807116/reviews) |
| Number of ratings | 1 | **6** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 18 MB | 69 MB |
| Requires iOS | 18.6 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Historycentral.com](https://appshunter.io/developer/1744330560) | [Agrian Inc.](https://appshunter.io/developer/333368745) |

## 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 |


### Simplot Advisor

[App page](https://appshunter.io/ios/app/simplot-advisor/id1361807116)

This app offers precision agronomy and compliance tools for crop advisors and growers. It enables seamless, real-time data syncing and offline capabilities for continuous productivity in the field. Advanced access requires a user account.

**Highlights:** Create and manage grower, farm, and field records, Offline editing and data management, Geo-referenced scouting observations with photos, Offline GPS-enabled soil and plant sample collection, Access in-season imagery and map overlays, Real-time cloud synchronization, Robust permissions model

**In-app purchases:** none


## Frequently asked questions

### Is Hydrology Formulator free?

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

### Is Simplot Advisor free?

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

### Which has better reviews, Hydrology Formulator or Simplot Advisor?

Hydrology Formulator is rated higher. Hydrology Formulator averages 5.0 out of 5 from 1 ratings, while Simplot Advisor averages 4.3 from 6 ratings.

### Do Hydrology Formulator or Simplot Advisor have ads?

Neither Hydrology Formulator nor Simplot Advisor shows ads.

### Which is updated more often, Hydrology Formulator or Simplot Advisor?

Hydrology Formulator ships an update every 6 months, and Simplot Advisor every 3 weeks. Most recently, Hydrology Formulator was updated on October 24, 2026 and Simplot Advisor on October 24, 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.*