# Seismometer vs Voltage Drop Pro

The clearest difference is update cadence: Voltage Drop Pro at every 2 months against Seismometer's every 13 months. Seismometer's advantage is price ($1.99 vs $3.99) and iOS requirement (8.0 vs 17.5). On ads, in-app purchases and device support there is nothing between them.

Seismometer costs $1.99 and Voltage Drop Pro $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Seismometer ships an update every 13 months, Voltage Drop Pro every 2 months. The most recent releases landed on September 30, 2026 and July 9, 2026 respectively.

## The numbers

| Metric | Seismometer | Voltage Drop Pro |
| --- | --- | --- |
| Price | **$1.99** | $3.99 |
| Rating | **[3.3 (17 ratings)](https://appshunter.io/ios/app/seismometer/id288966259/reviews)** | — |
| Number of ratings | **17** | — |
| Positive reviews | 64.7% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 13 months | **Every 2 months** |
| Monetization | Free | — |
| Size | 3 MB | 15 MB |
| Requires iOS | **8.0** | 17.5 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [FFFF00 Agents AB](https://appshunter.io/developer/288966262) | [Snappy Appz Inc.](https://appshunter.io/developer/375591377) |

## What reviewers say

### Seismometer

[App page](https://appshunter.io/ios/app/seismometer/id288966259)

This app uses your device's accelerometer to detect and measure vibrations, shakes, and movements. It calculates the energy of these movements and displays them on a logarithmic scale, offering various signal filters and recording capabilities.

**Highlights:** Measure vibrations and movements, Uses device accelerometer, Calculates energy of movements, Logarithmic scale display, Signal filters, Recordings and CSV export, UDP Streaming

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Sensitive and accurate
- 👍 Great for demonstrating vibrations
- 👍 Useful for photography and audio
- 👍 Visually appealing
- 👍 Clever use of accelerometer

**What reviewers complain about**

- 🐛 Crashes frequently
- 🐛 Inaccurate readings even on flat surfaces
- 🔋 Drains battery quickly
- 🔒 No security or privacy features
- 👎 Limited functionality and customization

**Reported bugs**

- Crashes when trying to view recordings
- Unresponsive controls
- Incompatible with newer iPhone models
- Screen turns off unexpectedly

**Requested features**

- Pause and scroll back through recordings
- Save and email recorded data
- Adjustable sensitivity settings
- Richter scale or other measurement units
- Ability to record and review vibration history


### Voltage Drop Pro

[App page](https://appshunter.io/ios/app/voltage-drop-pro/id1601052433)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Seismometer free?

Seismometer costs $1.99, with no in-app purchases.

### Is Voltage Drop Pro free?

Voltage Drop Pro costs $3.99, with no in-app purchases.

### Do Seismometer or Voltage Drop Pro have ads?

Neither Seismometer nor Voltage Drop Pro shows ads.

### Which is updated more often, Seismometer or Voltage Drop Pro?

Seismometer ships an update every 13 months, and Voltage Drop Pro every 2 months. Most recently, Seismometer was updated on September 30, 2026 and Voltage Drop Pro on July 9, 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.*