# Wastewater Treatment Level 3 vs Class 4 Knowledge Test

The clearest difference is in-app purchases: Class 4 Knowledge Test at none against Wastewater Treatment Level 3's 1. On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Wastewater Treatment Level 3 sells 1 in-app purchase, starting at $7.00 per month. Class 4 Knowledge Test asks for nothing beyond the download.

## The numbers

| Metric | Wastewater Treatment Level 3 | Class 4 Knowledge Test |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Size | 3 MB | 95 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Ambitionz Apps](https://appshunter.io/developer/1764753535) | [Quizzard Exam Preperation Inc.](https://appshunter.io/developer/1707617401) |

## What reviewers say

### Wastewater Treatment Level 3

[App page](https://appshunter.io/ios/app/wastewater-treatment-level-3/id6738367369)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Wastewater Treatment Level 3 | $7.00 | per month |


### Class 4 Knowledge Test

[App page](https://appshunter.io/ios/app/class-4-knowledge-test/id6796053563)

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

**In-app purchases:** none


## Frequently asked questions

### Is Wastewater Treatment Level 3 free?

Wastewater Treatment Level 3 is free to download, with in-app purchases available.

### Is Class 4 Knowledge Test free?

Class 4 Knowledge Test is free to download, with no in-app purchases.

### Do Wastewater Treatment Level 3 or Class 4 Knowledge Test have ads?

Neither Wastewater Treatment Level 3 nor Class 4 Knowledge Test 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.*