# CAS School vs Subtractor

The clearest difference is update cadence: Subtractor at every 8 days against CAS School's every 3 months. CAS School's advantage is iOS requirement (12.0 vs 15.6). On price, ads, in-app purchases and device support there is nothing between them.

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

CAS School ships an update every 3 months, Subtractor every 8 days. The most recent releases landed on October 30, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | CAS School | Subtractor |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 8 days** |
| Size | 103 MB | 0 MB |
| Requires iOS | **12.0** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [CodeHEX Solutions](https://appshunter.io/developer/1653264459) | [David Kelen](https://appshunter.io/developer/1796712157) |

## What reviewers say

### CAS School

[App page](https://appshunter.io/ios/app/cas-school/id6460300964)

**Features:** macOS Compatibility

**In-app purchases:** none


### Subtractor

[App page](https://appshunter.io/ios/app/subtractor-by-mather/id6742201502)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is CAS School free?

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

### Is Subtractor free?

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

### Do CAS School or Subtractor have ads?

Neither CAS School nor Subtractor shows ads.

### Which is updated more often, CAS School or Subtractor?

CAS School ships an update every 3 months, and Subtractor every 8 days. Most recently, CAS School was updated on October 30, 2026 and Subtractor on October 25, 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.*