# EIRP Calculator vs Hidden Mark

The clearest difference is price: EIRP Calculator at Free against Hidden Mark's $1.99. EIRP Calculator also leads on in-app purchases (none vs 3). Hidden Mark's advantage is update cadence (daily vs every 129 months) and iOS requirement (15.0 vs 17.5). On ads and device support there is nothing between them.

EIRP Calculator is free to download; Hidden Mark costs $1.99 up front. Hidden Mark sells 3 in-app purchases, starting at $1.99 per 7 days. EIRP Calculator asks for nothing beyond the download.

EIRP Calculator ships an update every 129 months, Hidden Mark daily. The most recent releases landed on October 26, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | EIRP Calculator | Hidden Mark |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 129 months | **Daily** |
| Size | 0 MB | 1 MB |
| Requires iOS | 17.5 | **15.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 9+ |
| Developer | [Pulsely Consulting](https://appshunter.io/developer/475349326) | [鸿斌 唐](https://appshunter.io/developer/1894765402) |

## What reviewers say

### EIRP Calculator

[App page](https://appshunter.io/ios/app/eirp-calculator/id785448118)

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

**In-app purchases:** none


### Hidden Mark

[App page](https://appshunter.io/ios/app/hidden-marktransmission-tools/id6762620428)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Premium | $1.99 | per 7 days |
| Monthly Premium | $2.99 | per month |
| Yearly Premium | $9.99 | per year |


## Frequently asked questions

### Is EIRP Calculator free?

EIRP Calculator is free to download, with no in-app purchases.

### Is Hidden Mark free?

Hidden Mark costs $1.99, and also offers in-app purchases.

### Do EIRP Calculator or Hidden Mark have ads?

Neither EIRP Calculator nor Hidden Mark shows ads.

### Which is updated more often, EIRP Calculator or Hidden Mark?

EIRP Calculator ships an update every 129 months, and Hidden Mark daily. Most recently, EIRP Calculator was updated on October 26, 2026 and Hidden Mark on October 28, 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.*