# Water Operator Prep vs Gauge

Water Operator Prep and Gauge are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. Water Operator Prep sells 2 in-app purchases, starting at $5.99 per 7 days and Gauge sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Water Operator Prep ships an update every 3 weeks, Gauge every 2 weeks. The most recent releases landed on October 17, 2026 and October 19, 2026 respectively.

## The numbers

| Metric | Water Operator Prep | Gauge |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 2 weeks** |
| Monetization | — | Free with in-app purchases |
| Size | 3 MB | 9 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Hermes Inteligencia Digital Ltda](https://appshunter.io/developer/1896694873) | [OMAR DANIEL GRAZIANO](https://appshunter.io/developer/1896485759) |

## What reviewers say

### Water Operator Prep

[App page](https://appshunter.io/ios/app/water-operator-prep-abc/id6789163062)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Water Operator Prep Weekly | $5.99 | per 7 days |
| Water Operator Prep Monthly | $14.99 | per month |


### Gauge

[App page](https://appshunter.io/ios/app/gauge-water-operator-prep/id6803531173)

Prepare for wastewater operator certification exams with a focus on the math section. This app offers free calculators for essential formulas and provides step-by-step solutions to common mistakes. Practice with timed exams that mirror the actual test format and weighting.

**Highlights:** Free operator math calculators, Step-by-step worked solutions, Timed practice exams, Formula selection drills, Offline functionality, Exam blueprint adherence

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Unlock | $14.99 | one-time |


## Frequently asked questions

### Is Water Operator Prep free?

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

### Is Gauge free?

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

### Do Water Operator Prep or Gauge have ads?

Neither Water Operator Prep nor Gauge shows ads.

### Which is updated more often, Water Operator Prep or Gauge?

Water Operator Prep ships an update every 3 weeks, and Gauge every 2 weeks. Most recently, Water Operator Prep was updated on October 17, 2026 and Gauge on October 19, 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.*