# Certification Prep Pro vs SOLID Architecture

The clearest difference is in-app purchases: Certification Prep Pro at none against SOLID Architecture's 3. SOLID Architecture's advantage is update cadence (every 9 days vs every 2 months) and iOS requirement (13.0 vs 17.5). 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. Certification Prep Pro asks for nothing beyond the download.

Certification Prep Pro ships an update every 2 months, SOLID Architecture every 9 days. The most recent releases landed on September 20, 2026 and September 28, 2026 respectively.

## The numbers

| Metric | Certification Prep Pro | SOLID Architecture |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 9 days** |
| Size | 17 MB | 94 MB |
| Requires iOS | 17.5 | **13.0** |
| Devices | iPhone | **iPhone, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Coffeedevs LLC](https://appshunter.io/developer/1793357959) | [Airton Siqueira de Freitas](https://appshunter.io/developer/1809776051) |

## What reviewers say

### Certification Prep Pro

[App page](https://appshunter.io/ios/app/certification-prep-pro/id6741158449)

**Features:** macOS Compatibility

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is Certification Prep Pro free?

Certification Prep Pro is free to download, with no in-app purchases.

### Is SOLID Architecture free?

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

### Do Certification Prep Pro or SOLID Architecture have ads?

Neither Certification Prep Pro nor SOLID Architecture shows ads.

### Which is updated more often, Certification Prep Pro or SOLID Architecture?

Certification Prep Pro ships an update every 2 months, and SOLID Architecture every 9 days. Most recently, Certification Prep Pro was updated on September 20, 2026 and SOLID Architecture on September 28, 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.*