# Gamma Calculator Pro vs API 570 Highlights Practices

The clearest difference is price: API 570 Highlights Practices at Free against Gamma Calculator Pro's $3.99. API 570 Highlights Practices also leads on rating (5.0 vs 3.6) and update cadence (every 2 months vs every 5 months). Gamma Calculator Pro's advantage is ratings volume (19 vs 1) and chart position (#11 vs unranked). On ads, in-app purchases and device support there is nothing between them.

API 570 Highlights Practices is free to download; Gamma Calculator Pro costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

API 570 Highlights Practices holds the better App Store score, 5.0 against 3.6. That said, the two scores are not equally well evidenced: Gamma Calculator Pro has 19 ratings behind it against 1, so its average is the more settled of the two.

Gamma Calculator Pro ships an update every 5 months, API 570 Highlights Practices every 2 months. The most recent releases landed on October 11, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Gamma Calculator Pro | API 570 Highlights Practices |
| --- | --- | --- |
| Price | $3.99 | **Free** |
| Rating | [3.6 (19 ratings)](https://appshunter.io/ios/app/gamma-calculator-pro/id867478383/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/api-570-highlights-practices/id1343650992/reviews)** |
| Number of ratings | **19** | 1 |
| Positive reviews | 52.9% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Best chart rank | **#11** | — |
| Size | 3 MB | 16 MB |
| Requires iOS | 18.6 | **9.1** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 17+ | 4+ |
| Developer | [Gerrit kleyn Winkel](https://appshunter.io/developer/797512757) | [Nguyen Hieu](https://appshunter.io/developer/1323491316) |

## What reviewers say

### Gamma Calculator Pro

[App page](https://appshunter.io/ios/app/gamma-calculator-pro/id867478383)

**Currently charting:** #11 Top Paid · Business (US App Store)

This app simplifies radiation exposure calculations for industrial radiography sources like Iridium-192. It allows users to input thickness, activity, and distance to determine correct exposure times, and also offers features for geometric unsharpness, exposure correction, and decay calculations.

**Highlights:** Exposure Time Calculator, Geometric Unsharpness Calculator, Exposure Correction Calculator, Decay Calculator, Barricade Calculator, Pipe Schedule Selector, Material Density Calculations

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

**In-app purchases:** none


### API 570 Highlights Practices

[App page](https://appshunter.io/ios/app/api-570-highlights-practices/id1343650992)

This free version offers a glimpse into piping inspection practices and exam questions. The full version provides over 1000 questions covering all sections of the API 570 Test.

**Highlights:** Practice questions, Exam simulations, Covers API 570 test sections, Free version available, Full version with 1000+ questions

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Gamma Calculator Pro free?

Gamma Calculator Pro costs $3.99, with no in-app purchases.

### Is API 570 Highlights Practices free?

API 570 Highlights Practices is free to download, with no in-app purchases.

### Which has better reviews, Gamma Calculator Pro or API 570 Highlights Practices?

API 570 Highlights Practices is rated higher. Gamma Calculator Pro averages 3.6 out of 5 from 19 ratings, while API 570 Highlights Practices averages 5.0 from 1 ratings.

### Do Gamma Calculator Pro or API 570 Highlights Practices have ads?

Neither Gamma Calculator Pro nor API 570 Highlights Practices shows ads.

### Which is updated more often, Gamma Calculator Pro or API 570 Highlights Practices?

Gamma Calculator Pro ships an update every 5 months, and API 570 Highlights Practices every 2 months. Most recently, Gamma Calculator Pro was updated on October 11, 2026 and API 570 Highlights Practices on October 15, 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.*