# WPI Exam Prep vs Wastewater Operator Prep

The clearest difference is in-app purchases: WPI Exam Prep at none against Wastewater Operator Prep's 3. Wastewater Operator Prep's advantage is update cadence (monthly vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Wastewater Operator Prep sells 3 in-app purchases, starting at $5.99 per 7 days. WPI Exam Prep asks for nothing beyond the download.

WPI Exam Prep ships an update every 3 months, Wastewater Operator Prep monthly. The most recent releases landed on November 9, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | WPI Exam Prep | Wastewater Operator Prep |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.5 (2 ratings)](https://appshunter.io/ios/app/wastewater-operator-prep-exam/id6789188108/reviews)** |
| Number of ratings | — | **2** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | — | Free with in-app purchases |
| Size | 120 MB | 9 MB |
| Requires iOS | **16.4** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Memorang](https://appshunter.io/developer/1011440560) | [Hermes Inteligencia Digital Ltda](https://appshunter.io/developer/1896694873) |

## What reviewers say

### WPI Exam Prep

[App page](https://appshunter.io/ios/app/wpi-exam-prep/id6754835308)

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

**In-app purchases:** none


### Wastewater Operator Prep

[App page](https://appshunter.io/ios/app/wastewater-operator-prep-exam/id6789188108)

Prepare for your wastewater operator certification exam with extensive practice questions and detailed explanations. This app covers all treatment processes and offers personalized study plans, timed modes, and progress tracking to boost your confidence and understanding.

**Highlights:** 1,027 practice questions, Detailed explanations for each answer, Full treatment process coverage, Personalized daily study plans, Timed practice modes, Progress tracking and pass probability

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Wastewater Prep Weekly | $5.99 | per 7 days |
| Wastewater Prep Monthly | $14.99 | per month |
| Quarterly | $29.99 | per 3 months |


## Frequently asked questions

### Is WPI Exam Prep free?

WPI Exam Prep is free to download, with no in-app purchases.

### Is Wastewater Operator Prep free?

Wastewater Operator Prep is free to download, with in-app purchases available.

### Do WPI Exam Prep or Wastewater Operator Prep have ads?

Neither WPI Exam Prep nor Wastewater Operator Prep shows ads.

### Which is updated more often, WPI Exam Prep or Wastewater Operator Prep?

WPI Exam Prep ships an update every 3 months, and Wastewater Operator Prep monthly. Most recently, WPI Exam Prep was updated on November 9, 2026 and Wastewater Operator Prep on November 5, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*