# Physical Science vs SJT Prep

The clearest difference is price: SJT Prep at Free against Physical Science's $15.99. Physical Science's advantage is in-app purchases (none vs 3). On update cadence, ads, device support and iOS requirement there is nothing between them.

SJT Prep is free to download; Physical Science costs $15.99 up front. SJT Prep sells 3 in-app purchases, starting at $6.99 per 7 days. Physical Science asks for nothing beyond the download.

Physical Science ships an update every 3 months, SJT Prep every 2 months. The most recent releases landed on October 12, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Physical Science | SJT Prep |
| --- | --- | --- |
| Price | $15.99 | **Free** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 2 months** |
| Size | 45 MB | 102 MB |
| Requires iOS | 15.0 | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Willie van Schalkwyk](https://appshunter.io/developer/1016415734) | [Alpha Beat Limited](https://appshunter.io/developer/1745742707) |

## What reviewers say

### Physical Science

[App page](https://appshunter.io/ios/app/physical-science-high-school/id1393843475)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### SJT Prep

[App page](https://appshunter.io/ios/app/sjt-prep-casper-test-practice/id6794435150)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly | $6.99 | per 7 days |
| Monthly | $19.99 | per month |
| Lifetime | $49.99 | one-time |


## Frequently asked questions

### Is Physical Science free?

Physical Science costs $15.99, with no in-app purchases.

### Is SJT Prep free?

SJT Prep is free to download, with in-app purchases available.

### Do Physical Science or SJT Prep have ads?

Neither Physical Science nor SJT Prep shows ads.

### Which is updated more often, Physical Science or SJT Prep?

Physical Science ships an update every 3 months, and SJT Prep every 2 months. Most recently, Physical Science was updated on October 12, 2026 and SJT Prep 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.*