# CLEP Natural Science Test Prep vs σT

The clearest difference is in-app purchases: σT at none against CLEP Natural Science Test Prep's 9. σT also leads on update cadence (fortnightly vs every 16 months). CLEP Natural Science Test Prep's advantage is iOS requirement (15.1 vs 26.2). On price, ads and device support there is nothing between them.

Both are free to download. CLEP Natural Science Test Prep sells 9 in-app purchases, starting at $8.99 per 7 days. σT asks for nothing beyond the download.

CLEP Natural Science Test Prep ships an update every 16 months, σT fortnightly. Both last shipped on October 30, 2026.

## The numbers

| Metric | CLEP Natural Science Test Prep | σT |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 16 months | **Fortnightly** |
| Size | 53 MB | 6 MB |
| Requires iOS | **15.1** | 26.2 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [YAUHEN BAHDANOVICH](https://appshunter.io/developer/1711932790) | [YARON AMIR BENJAMIN DR. GOLDSTEIN](https://appshunter.io/developer/1850455880) |

## What reviewers say

### CLEP Natural Science Test Prep

[App page](https://appshunter.io/ios/app/clep-natural-science-test-prep/id6741392610)

**Features:** macOS Compatibility

**In-app purchases (9)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sciences Weekly Full Access | $8.99 | per 7 days |
| Sciences Monthly Full Access | $24.99 | per month |
| Science Monthly Full Access | $34.99 | per month |
| Science Quarterly Full Access | $55.99 | per 3 months |
| Science Quarterly Full Access | $59.99 | per 3 months |
| Science Semiannual Full Access | $75.99 | per 6 months |
| Science Semiannual Full Access | $79.99 | per 6 months |
| Science Annual Full Access | $109.99 | per year |
| Science Annual Full Access | $119.99 | per year |


### σT

[App page](https://appshunter.io/ios/app/t/id6756549182)

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

**In-app purchases:** none


## Frequently asked questions

### Is CLEP Natural Science Test Prep free?

CLEP Natural Science Test Prep is free to download, with in-app purchases available.

### Is σT free?

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

### Do CLEP Natural Science Test Prep or σT have ads?

Neither CLEP Natural Science Test Prep nor σT shows ads.

### Which is updated more often, CLEP Natural Science Test Prep or σT?

CLEP Natural Science Test Prep ships an update every 16 months, and σT fortnightly. Most recently, CLEP Natural Science Test Prep was updated on October 30, 2026 and σT on October 30, 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.*