iSeismometer vs Stratostar
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
Stratostar
Monitor and communicate with StratoStar electronics on the ground before a launch. Connect via Wi-Fi to display sensor data from the SatCom Flight Computer. Designed for use in close proximity to the device.
- Ground monitoring
- Communication with electronics
- Wi-Fi connectivity
- Sensor data display
- Compatible with SatCom Flight Computer
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The StratoStar App allows you to monitor and communicate with your StratoStar electronics on the ground before a launch. StratoStar is an Aerospace company founded in 2006, delivering end-to-end high-altitude weather ballooning equipment, avionics, software, training, curriculum, and launch services for aerospace and education organizations. This application is compatible with StratoStar’s SatCom Flight Computer. Download the application and use Wifi to connect directly with your SatCom Flight Computer. When connected, data will be displayed on the application from the sensors within the SatCom Flight Computer. This application is intended for use on the ground with close proximity to SatCom (2-3ft). For tracking the SatCom while in flight, you will need to monitor the Mission Page online, which is provided by your Flight Director and has been previously scheduled. For more information on StratoStar’s products and services related to weather balloons and high-altitude balloons, visit www.StratoStar.com
Screenshots
Verdict
The clearest difference is rating: Stratostar at 5.0 against iSeismometer's 3.6. iSeismometer's advantage is ratings volume (170 vs 1). On price, update cadence, ads and in-app purchases 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.
Stratostar holds the better App Store score, 5.0 against 3.6. That said, the two scores are not equally well evidenced: iSeismometer has 170 ratings behind it against 1, so its average is the more settled of the two.
iSeismometer ships an update every 7 months, Stratostar every 10 months. The most recent releases landed on October 17, 2026 and October 13, 2026 respectively.
| Parameter | iSeismometer | Stratostar |
|---|---|---|
| Price | Free | Free |
| Rating | 3.6 (170 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 76.5% of reviews | — |
| Number of ratings | 170 — better | 1 |
| Update frequency | Every 7 months — better | Every 10 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, Mac — better | iPhone, iPad |
| Requires iOS | 16.0 | 16.0 |
| Further details — not scored | ||
| Size | 3 MB | 8 MB |
| Age rating | 4+ | 4+ |
| Developer | ObjectGraph LLC | AJ Technologies LLC |
Customer experience
iSeismometer
Stratostar
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)
Stratostar
Not enough reviews yet to summarise bugs or requests.
In-app purchases
iSeismometer
No in-app purchases
Stratostar
No in-app purchases
Questions
Is iSeismometer free?
Is Stratostar free?
Which has better reviews, iSeismometer or Stratostar?
Do iSeismometer or Stratostar have ads?
Which is updated more often, iSeismometer or Stratostar?
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