# NDT Events vs API 571 Helpmate

The clearest difference is in-app purchases: NDT Events at none against API 571 Helpmate's 1. NDT Events also leads on device support (4 vs 2). On price, update cadence, ads and iOS requirement there is nothing between them.

Both are free to download. API 571 Helpmate sells 1 in-app purchase, starting at $29.00 per year. NDT Events asks for nothing beyond the download.

NDT Events ships an update every 5 months, API 571 Helpmate every 8 months. The most recent releases landed on October 10, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | NDT Events | API 571 Helpmate |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 8 months |
| Size | 7 MB | 34 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [The British Institute of Non-Destructive Testing](https://appshunter.io/developer/554280129) | [Austenite Pty Ltd](https://appshunter.io/developer/1525502686) |

## What reviewers say

### NDT Events

[App page](https://appshunter.io/ios/app/ndt-events/id1129755816)

**In-app purchases:** none


### API 571 Helpmate

[App page](https://appshunter.io/ios/app/api-571-helpmate/id6746396841)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 12 Months Plan | $29.00 | per year |


## Frequently asked questions

### Is NDT Events free?

NDT Events is free to download, with no in-app purchases.

### Is API 571 Helpmate free?

API 571 Helpmate is free to download, with in-app purchases available.

### Do NDT Events or API 571 Helpmate have ads?

Neither NDT Events nor API 571 Helpmate shows ads.

### Which is updated more often, NDT Events or API 571 Helpmate?

NDT Events ships an update every 5 months, and API 571 Helpmate every 8 months. Most recently, NDT Events was updated on October 10, 2026 and API 571 Helpmate on October 15, 2026.

---

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