# The Fourth Dimension vs Testseries Alchemys

The clearest difference is price: Testseries Alchemys at Free against The Fourth Dimension's $2.99. The Fourth Dimension's advantage is in-app purchases (none vs 10) and update cadence (every 4 months vs every 12 months). On ads, device support and iOS requirement there is nothing between them.

Testseries Alchemys is free to download; The Fourth Dimension costs $2.99 up front. Testseries Alchemys sells 10 one-off in-app purchases. The Fourth Dimension asks for nothing beyond the download.

The Fourth Dimension ships an update every 4 months, Testseries Alchemys every 12 months. The most recent releases landed on November 10, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | The Fourth Dimension | Testseries Alchemys |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[4.8 (1.9K ratings)](https://appshunter.io/ios/app/the-fourth-dimension/id504201783/reviews)** | — |
| Number of ratings | **1.9K** | — |
| Positive reviews | 94.2% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 12 months |
| Monetization | Free with in-app purchases | — |
| Size | 5 MB | 146 MB |
| Requires iOS | **15.0** | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | +4 | 4+ |
| Developer | [Lunar Skydiving LLC](https://appshunter.io/developer/504201786) | [Online Learning](https://appshunter.io/developer/1790866777) |

## What reviewers say

### The Fourth Dimension

[App page](https://appshunter.io/ios/app/the-fourth-dimension/id504201783)

Explore a complex mathematical concept through an interactive 3D experience. This app uses a unique touch interface to help you visualize and understand the fourth dimension in an engaging and accessible way.

**Highlights:** Interactive 3D touch interface, Explains the fourth dimension, Accessible language for all, 30-page interactive book, Visual and hands-on learning

**In-app purchases:** none


### Testseries Alchemys

[App page](https://appshunter.io/ios/app/testseries-alchemys/id6472882696)

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Package - 21900 | $199.99 | one-time |
| Package - 19900 | $199.99 | one-time |
| Package - 29900 | $299.99 | one-time |
| Package - 27900 | $299.99 | one-time |
| Package - 34900 | $349.99 | one-time |
| Package - 54900 | $499.99 | one-time |
| Package - 59900 | $599.99 | one-time |
| Package - 69900 | $699.99 | one-time |
| Package - 79900 | $799.99 | one-time |
| Package - 89900 | $899.99 | one-time |


## Frequently asked questions

### Is The Fourth Dimension free?

The Fourth Dimension costs $2.99, with no in-app purchases.

### Is Testseries Alchemys free?

Testseries Alchemys is free to download, with in-app purchases available.

### Do The Fourth Dimension or Testseries Alchemys have ads?

Neither The Fourth Dimension nor Testseries Alchemys shows ads.

### Which is updated more often, The Fourth Dimension or Testseries Alchemys?

The Fourth Dimension ships an update every 4 months, and Testseries Alchemys every 12 months. Most recently, The Fourth Dimension was updated on November 10, 2026 and Testseries Alchemys on November 8, 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.*