Comparison

iSeismometer vs REDACt EU

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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

About

REDACt EU

Read full description

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

iSeismometer4 screens
REDACt EU4 screens

Verdict

The call

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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

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.

Scorecard2 real differences · 8 level
iSeismometer versus REDACt EU: the parameters behind the verdict, then further details
ParameteriSeismometerREDACt EU
PriceFreeFree
Rating3.6 (170 ratings) — better—
Positive reviews76.5% of reviews—
Number of ratings170 — better—
Update frequencyEvery 7 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, MaciPhone, iPad, iPod
Requires iOS16.013.0 — better
Further details — not scored
Size3 MB84 MB
Age rating4+4+
DeveloperObjectGraph LLCRedvector 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
Show 1 more
  • 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

None

iSeismometer

No in-app purchases

None

REDACt EU

No in-app purchases

Questions

Is iSeismometer free?
iSeismometer is free to download, with no in-app purchases.
Is REDACt EU free?
REDACt EU is free to download, with no in-app purchases.
Do iSeismometer or REDACt EU have ads?
Neither iSeismometer nor REDACt EU shows ads.
Which is updated more often, iSeismometer or REDACt EU?
iSeismometer ships an update every 7 months, and REDACt EU every 3 weeks. Most recently, iSeismometer was updated on October 17, 2026 and REDACt EU on October 8, 2026.

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