# MartleyRocks vs Groundwater App

The clearest difference is update cadence: Groundwater App at every 6 months against MartleyRocks's every 46 months. Groundwater App also leads on iOS requirement (6.0 vs 11.0). MartleyRocks's advantage is device support (3 vs 1). On price, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

MartleyRocks ships an update every 46 months, Groundwater App every 6 months. The most recent releases landed on October 14, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | MartleyRocks | Groundwater App |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/groundwater-app/id1036868330/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 46 months | **Every 6 months** |
| Monetization | — | Free |
| Size | 65 MB | 63 MB |
| Requires iOS | 11.0 | **6.0** |
| Devices | **iPhone, iPad, iPod** | iPad |
| Age rating | 4+ | 4+ |
| Developer | [Michael Brooks](https://appshunter.io/developer/526071845) | [Koboldgames GmbH](https://appshunter.io/developer/933187097) |

## What reviewers say

### MartleyRocks

[App page](https://appshunter.io/ios/app/martleyrocks/id1006570855)

**Features:** macOS Compatibility

**In-app purchases:** none


### Groundwater App

[App page](https://appshunter.io/ios/app/groundwater-app/id1036868330)

Explore the origins, uses, and river connections of groundwater through three engaging chapters. Conduct experiments in a virtual lab to deepen your understanding of groundwater behavior.

**Highlights:** Three learning chapters, Groundwater origins explained, Groundwater uses detailed, Link between groundwater and rivers, Virtual groundwater lab, Interactive experiments

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is MartleyRocks free?

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

### Is Groundwater App free?

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

### Do MartleyRocks or Groundwater App have ads?

Neither MartleyRocks nor Groundwater App shows ads.

### Which is updated more often, MartleyRocks or Groundwater App?

MartleyRocks ships an update every 46 months, and Groundwater App every 6 months. Most recently, MartleyRocks was updated on October 14, 2026 and Groundwater App on October 10, 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.*