iSeismometer vs REDACt EU
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
iSeismometer
Transform your iPhone into a sensitive seismometer to detect and visualize vibrations. Explore its educational and data-collecting capabilities for fun or serious applications.
- Converts iPhone to seismometer
- Detects and visualizes vibrations
- Data collecting capabilities
- Educational use
- Adjustable frequency settings
- Re-track previous data
- X-Y-Z illustrated graphs
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iSeismometer turns your iPhone or iPad into a seismograph. Set it on a table, tap the desk, and watch the ground move. You will be surprised how sensitive your phone is. It has been doing that since the App Store opened in 2008, when it reached #1 in Education in Japan, Austria, Finland, and Greece. Version 1.7 is a complete rebuild: faster, clearer, and finally a real instrument. LIVE SEISMOGRAPH • Three axes at up to 100 samples per second, drawn like a strip-chart recorder • Scroll back through up to an hour of history while it keeps recording • Gravity filter with a real corner frequency, so slow tilt disappears and earthquakes stay • Live spectrum: see the frequency of footsteps, a washing machine, or a passing truck at a glance • Dark mode and a full iPad layout EVENT DETECTION • A seismologist's STA/LTA trigger flags every tremor with its peak acceleration, duration, and dominant frequency • Three sensitivity levels, from "only real shakes" to "every footstep" • Events are shaded on the traces and listed so you can jump straight to them RECORDINGS • Every session is saved automatically as compact raw data, split into hourly files • Browse by day, open any recording, scrub to its events, and see its spectrum • Export CSV, or pick up the raw files in the Files app and in Finder • Keep them for a day, a week, a month, or forever WAS THAT AN EARTHQUAKE? • Live USGS feed on a globe, filtered by time window and magnitude • Tap a quake for its depth, time, and the official USGS page STREAM TO YOUR MAC • Open iSeismometer on a Mac on the same Wi-Fi and your phone finds it by itself • The Mac shows every device streaming to it side by side, with its own recordings and event detection • Reconnects on its own after the screen locks, the network drops, or the Mac restarts Made for fun and for learning. A phone carries a MEMS accelerometer, not a broadband seismometer, so it feels footsteps and trucks far better than distant earthquakes. Put it on a solid floor, plug it in, keep the screen awake, and you have a home seismic station. iSeismometer is not a substitute for official earthquake early warnings or emergency alerts. Questions and ideas: info@objectgraph.com "This is a novelty app but one that also helps you learn something new... one of those things that is very captivating once you've looked at it once." — The Independent Guide to the iPhone 3GS
REDACt EU
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REDACt is a powerful earthquake monitoring app which delivers all of the information you need, with push notifications included, all free of charge. It also includes a beautifully simple design optimized for the latest versions of iOS.
Screenshots
Verdict
The clearest difference is update cadence: REDACt EU at every 3 weeks against iSeismometer's every 7 months. REDACt EU also leads on iOS requirement (13.0 vs 16.0). On price, 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
iSeismometer ships an update every 7 months, REDACt EU every 3 weeks. The most recent releases landed on October 17, 2026 and October 8, 2026 respectively.
| Parameter | iSeismometer | REDACt EU |
|---|---|---|
| Price | Free | Free |
| Rating | 3.6 (170 ratings) — better | — |
| Positive reviews | 76.5% of reviews | — |
| Number of ratings | 170 — better | — |
| Update frequency | Every 7 months | Every 3 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Requires iOS | 16.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 3 MB | 84 MB |
| Age rating | 4+ | 4+ |
| Developer | ObjectGraph LLC | Redvector SRL |
Bugs and requests
iSeismometer
Reported bugs
3 issues- Buttons/controls not working on newer iOS versions
- Keyboard not appearing in text input fields
- Inconsistent performance across device models
Requested features
6 requests- Add sensitivity control
- Implement zero control for reference plane
- Increase recording time
- Improve UI/UX (e.g. color coding, scrolling, chart speed control)
- Implement Richter scale or other measurement units
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- Add data export/sharing options (e.g. email, save to file)
REDACt EU
Not enough reviews yet to summarise bugs or requests.
In-app purchases
iSeismometer
No in-app purchases
REDACt EU
No in-app purchases
Questions
Is iSeismometer free?
Is REDACt EU free?
Do iSeismometer or REDACt EU have ads?
Which is updated more often, iSeismometer or REDACt EU?
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