Seismometer vs Voltage Drop Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Seismometer
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.
- Measure vibrations and movements
- Uses device accelerometer
- Calculates energy of movements
- Logarithmic scale display
- Signal filters
- Recordings and CSV export
- UDP Streaming
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Measure everything that vibrates, shakes or moves. Or why not an actual earthquake? Seismometer uses your iPhone's built in accelerometer to measure movements in two axes, calculate the resulting energy and draw the results on a rolling logarithmic scale. Features: * Different signal filters * Highly configurable * Recordings * CSV exporting of recordings * UDP Streaming http://yellowagents.com/seismometer/ for more info and examples of how to use the streaming protocol.
Voltage Drop Pro
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Voltage Drop Calc is a fast, easy way to create a schedule of voltage drop calculations for any size of job or just to perform a single calculation on the fly. Put your pencil down and start making professional, consistent calculation today. - Universal app allows use on both iPad, and iPhone/iPod with single purchase. - Create an unlimited list of calculations that automatically save. - Export your results to a spreadsheet for formatting or printing. - Solve for distance in feet or meters. - Solve for voltage drop in either voltage or percentage. - Solve for wire size including derating. - Built in construction calculator allows intermediate calculations to be performed within the app.
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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 28, 2026 and July 9, 2026 respectively.
| Parameter | Seismometer | Voltage Drop Pro |
|---|---|---|
| Price | $1.99 — better | $3.99 |
| Rating | 3.3 (17 ratings) — better | — |
| Positive reviews | 64.7% of reviews | — |
| Number of ratings | 17 — better | — |
| Update frequency | Every 13 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 8.0 — better | 17.5 |
| Further details — not scored | ||
| Size | 3 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | FFFF00 Agents AB | Snappy Appz Inc. |
Bugs and requests
Seismometer
Reported bugs
4 issues- Crashes when trying to view recordings
- Unresponsive controls
- Incompatible with newer iPhone models
- Screen turns off unexpectedly
Requested features
5 requests- 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
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Seismometer
No in-app purchases
Voltage Drop Pro
No in-app purchases
Questions
Is Seismometer free?
Is Voltage Drop Pro free?
Do Seismometer or Voltage Drop Pro have ads?
Which is updated more often, Seismometer or Voltage Drop Pro?
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