# WaterQuality vs FOTJ

The clearest difference is price: FOTJ at Free against WaterQuality's $4.99. FOTJ also leads on update cadence (every 4 days vs every 5 months). WaterQuality's advantage is chart position (#197 vs unranked) and iOS requirement (11.0 vs 17.4). On ads, in-app purchases and device support there is nothing between them.

FOTJ is free to download; WaterQuality costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

WaterQuality ships an update every 5 months, FOTJ every 4 days. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.

## The numbers

| Metric | WaterQuality | FOTJ |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/waterquality/id569193509/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 4 days** |
| Monetization | Paid | — |
| Best chart rank | **#197** | — |
| Size | 96 MB | 2 MB |
| Requires iOS | **11.0** | 17.4 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, Apple Watch |
| Age rating | 4+ | 4+ |
| Developer | [Stroud Water Research Center](https://appshunter.io/developer/1200990268) | [Rodney Dyer](https://appshunter.io/developer/1710556824) |

## What reviewers say

### WaterQuality

[App page](https://appshunter.io/ios/app/waterquality/id569193509)

**Currently charting:** #197 Top Paid · Education (US App Store)

This educational app allows users of all ages to record stream study data and learn about water quality indicators. It functions offline and includes a field guide for identifying aquatic macroinvertebrates to assess pollution tolerance. Data can be exported for scientific research or educational purposes.

**Highlights:** Record stream study data, Learn about water quality indicators, Offline functionality, Macroinvertebrate field guide, Data export (print/email), Site location recording

**Features:** Vision Pro support

**In-app purchases:** none


### FOTJ

[App page](https://appshunter.io/ios/app/fotj/id6502670309)

**In-app purchases:** none


## Frequently asked questions

### Is WaterQuality free?

WaterQuality costs $4.99, with no in-app purchases.

### Is FOTJ free?

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

### Do WaterQuality or FOTJ have ads?

Neither WaterQuality nor FOTJ shows ads.

### Which is updated more often, WaterQuality or FOTJ?

WaterQuality ships an update every 5 months, and FOTJ every 4 days. Most recently, WaterQuality was updated on November 1, 2026 and FOTJ on November 4, 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.*