# Ghost Detector EMF Necrometer vs Harmonograph

The clearest difference is in-app purchases: Harmonograph at none against Ghost Detector EMF Necrometer's 4. Ghost Detector EMF Necrometer's advantage is ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Ghost Detector EMF Necrometer sells 4 in-app purchases, starting at $4.99 per 7 days. Harmonograph asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 10 days. Both last shipped on October 24, 2026.

## The numbers

| Metric | Ghost Detector EMF Necrometer | Harmonograph |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (440 ratings)](https://appshunter.io/ios/app/ghost-detector-emf-necrometer/id6754881764/reviews)** | — |
| Number of ratings | **440** | — |
| Positive reviews | 54.3% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 10 days | Every 10 days |
| Monetization | Subscription | — |
| Size | 68 MB | 5 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 9+ | 4+ |
| Developer | [Boss Web SRL](https://appshunter.io/developer/1839514881) | [Takashi Nemoto](https://appshunter.io/developer/6790828928) |

## What reviewers say

### Ghost Detector EMF Necrometer

[App page](https://appshunter.io/ios/app/ghost-detector-emf-necrometer/id6754881764)

This app combines EMF detection with a spirit box to facilitate paranormal communication. It offers professional-grade tools for real-time environmental monitoring and authentic voice manifestations, designed for both enthusiasts and experienced investigators.

**Highlights:** EMF Magnetic Energy Detection, DR60 Spirit Box Sound Bank, Phoneme-Based Audio Generation, 9 Sound Banks and White Noise, Spoken Response System (Text-to-Speech), Built-In Audio Effects (Echo, Reverb), Advanced Paranormal Tools (Waveform Display)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Plan | $4.99 | per 7 days |
| Monthly Plan | $9.99 | per month |
| Special Offer | $14.99 | one-time |
| Lifetime Plan | $29.99 | one-time |


### Harmonograph

[App page](https://appshunter.io/ios/app/harmonograph-pendulum-art/id6794857269)

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

**In-app purchases:** none


## Frequently asked questions

### Is Ghost Detector EMF Necrometer free?

Ghost Detector EMF Necrometer is free to download, with in-app purchases available.

### Is Harmonograph free?

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

### Do Ghost Detector EMF Necrometer or Harmonograph have ads?

Harmonograph shows ads; Ghost Detector EMF Necrometer does not.

### Which is updated more often, Ghost Detector EMF Necrometer or Harmonograph?

Ghost Detector EMF Necrometer ships an update every 10 days, and Harmonograph every 10 days. Most recently, Ghost Detector EMF Necrometer was updated on October 24, 2026 and Harmonograph on October 24, 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.*