# SOLID Architecture vs Set Theory for Computing

The clearest difference is in-app purchases: Set Theory for Computing at none against SOLID Architecture's 3. SOLID Architecture's advantage is iOS requirement (13.0 vs 15.1). On price, ads and device support there is nothing between them.

Both are free to download. SOLID Architecture sells 3 one-off in-app purchases. Set Theory for Computing asks for nothing beyond the download.

## The numbers

| Metric | SOLID Architecture | Set Theory for Computing |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 9 days | — |
| Size | 94 MB | 38 MB |
| Requires iOS | **13.0** | 15.1 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Airton Siqueira de Freitas](https://appshunter.io/developer/1809776051) | [AFTW LLC](https://appshunter.io/developer/1886356149) |

## What reviewers say

### SOLID Architecture

[App page](https://appshunter.io/ios/app/solid-architecture/id6755614891)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| CERTIFICATE OF COMPLETION | $2.99 | one-time |
| Premium access | $4.99 | one-time |
| FULL PASS ALL APPS | $17.99 | one-time |


### Set Theory for Computing

[App page](https://appshunter.io/ios/app/set-theory-for-computing/id6773874925)

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

**In-app purchases:** none


## Frequently asked questions

### Is SOLID Architecture free?

SOLID Architecture is free to download, with in-app purchases available.

### Is Set Theory for Computing free?

Set Theory for Computing is free to download, with no in-app purchases.

### Do SOLID Architecture or Set Theory for Computing have ads?

Neither SOLID Architecture nor Set Theory for Computing 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.*