# Earth Primer vs Physical Changes in Matter

The clearest difference is price: Physical Changes in Matter at Free against Earth Primer's $9.99. Physical Changes in Matter also leads on device support (3 vs 1). Earth Primer's advantage is iOS requirement (7.0 vs 12.0). On ads and in-app purchases there is nothing between them.

Physical Changes in Matter is free to download; Earth Primer costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

## The numbers

| Metric | Earth Primer | Physical Changes in Matter |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[4.7 (35 ratings)](https://appshunter.io/ios/app/earth-primer/id956678532/reviews)** | — |
| Number of ratings | **35** | — |
| Positive reviews | 75.4% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | — |
| Monetization | Paid | — |
| Size | 185 MB | 30 MB |
| Requires iOS | **7.0** | 12.0 |
| Devices | iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Chaim Gingold](https://appshunter.io/developer/328361943) | [Science Education Institute](https://appshunter.io/developer/1439710468) |

## What reviewers say

### Earth Primer

[App page](https://appshunter.io/ios/app/earth-primer/id956678532)

Explore Earth's geological processes through interactive play. Sculpt mountains, create volcanoes, and manipulate natural forces to understand planetary science in a fun, engaging way.

**Highlights:** Discover how Earth works through play, Control natural forces like volcanoes and tectonic plates, 20 different tools to unlock, Richly interactive geological simulations, Five chapters: Earth's Interior, Surface, Water Cycle, Biomes, and Sandbox, Sandbox mode for open-ended play

**In-app purchases:** none

**What reviewers like**

- 💡 Brilliant educational tool
- 👍 Intuitive and interactive simulations
- ✨ Stunning graphics and artful illustrations
- 🚀 Excellent for learning geology
- 🤩 Fun and engaging for all ages

**What reviewers complain about**

- 🐛 Some options grayed out in sandbox mode
- 🤔 Lacks depth in certain simulations
- 😕 Interface can be confusing for new users
- 📉 Some users find it boring after initial use
- 💰 Expensive for some users

**Reported bugs**

- 🐛 Grayed out options in sandbox mode on iOS 12.1.3
- 🐛 Unreadable on iPad Pro
- 🐛 Broken software on iPad Pro
- 🐛 Still not working on iPad Pro
- 🐛 Does not work on iPad Pro

**Requested features**

- Add a sandbox version for 2D earth
- Add 3D models for volcanoes
- Include simulated volcanic eruptions, earthquakes, and tsunamis
- Add a sandbox simulation program for these phenomena
- Add humans and animals to sandbox mode to observe civilization building and impact


### Physical Changes in Matter

[App page](https://appshunter.io/ios/app/physical-changes-in-matter/id6514314103)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Earth Primer free?

Earth Primer costs $9.99, with no in-app purchases.

### Is Physical Changes in Matter free?

Physical Changes in Matter is free to download, with no in-app purchases.

### Do Earth Primer or Physical Changes in Matter have ads?

Neither Earth Primer nor Physical Changes in Matter shows ads.

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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.*