Comparison

CASSY App vs phyphox

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

Head to head
About

CASSY App

Control scientific measurement devices and display data on your mobile device. Analyze, store, and share results without a PC. Supports a wide range of physics, chemistry, and biology sensors.

Highlights
  • Control CASSY devices
  • Display measurements (analog/digital, tables, diagrams)
  • Evaluate and store data
  • Share results wirelessly
  • Support for physics, chemistry, and biology sensors
  • WebDAV server integration
Features
Read full description

With the CASSY App, students and teachers can measure, observe and analyse using CASSY – on an iPad or iPhone. It’s simple and practical for everyday use: just type in the PIN from the CASSY display or scan the QR code and start measuring straight away. - Free experimentation without fixed experimental parameters - Group measurements: connect up to 4 devices to a single CASSY simultaneously - Live measurement results on an external display in digital and analogue displays, tables and diagrams - Free configuration of measurements - Comparison of multiple measurements - Individual evaluation per student - Save results and load measured values for analysis - Exam mode for exam security (configurable via CASSY teaching profiles on our LeyLab online portal) - Can be used without internet access The CASSY App supports all CASSY sensors and the following CASSY devices: - Mobile-CASSY 2 WiFi (524 005W2, 524 005W) - Power Analyser CASSY (727 101, 727 111) - Machine Test CASSY (773 1901, 773 2901) - Converter Controller CASSY (773 5291) - Power Control CASSY (773 530) You can obtain a compatible CASSY and the sensors from LD DIDACTIC GmbH. Further information can be found on our website.

About

phyphox

Unlock your phone's sensors for scientific exploration. Conduct pre-built experiments or create your own using accelerometers, magnetometers, and more. Analyze and export data in various formats for further study.

Highlights
  • Pre-defined experiments
  • Data export (CSV, TSV, Excel)
  • Web-based remote control
  • Custom experiment editor
  • Access to phone sensors
  • Advanced analysis functions
Features
Read full description

Did you know that you are carrying a 3D magnetometer? That you can use your phone as a pendulum to measure earth's local gravitational acceleration? That you can turn your phone into a sonar? phyphox gives you access to the sensors of your phone either directly or through ready-to-play experiments which analyze your data and let you export raw data along with the results for further analysis. You can even define your own experiments on phyphox.org and share them with colleagues, students and friends. Selected Features: • A selection of pre-defined experiments. Just press play to start. • Export your data to a range of widely used formats • Remote-control your experiment through a web interface from any PC on the same network as your phone. No need to install anything on those PCs - all you need is a modern web browser. • Define your own experiments by selecting sensor inputs, defining analysis steps and creating views as an interface using our web-editor (http://phyphox.org/editor). The analysis consists of just adding two values or using advanced methods like Fourier transforms and crosscorrelation. We offer a whole toolbox of analysis functions. Sensors supported: • Accelerometer • Magnetometer • Gyroscope • Pressure • Microphone • Proximity • GPS • Camera • LiDAR/ToF *some sensors are not present on every phone. Export formats • CSV (Comma separated values) • TSV (Tab-separated values) • Excel (if you need other formats, please let us know) This app has been developed at the 2nd Institute of Physics A at the RWTH Aachen University.

Screenshots

CASSY App4 screens
phyphox4 screens

Verdict

The call

The clearest difference is review sentiment: phyphox at 79% against CASSY App's 60%. phyphox also leads on iOS requirement (12.0 vs 15.0). 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

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

Both ship on a similar rhythm, roughly every 3 months. Both last shipped on October 24, 2026.

Scorecard2 real differences · 8 level
CASSY App versus phyphox: the parameters behind the verdict, then further details
ParameterCASSY Appphyphox
PriceFreeFree
Rating—4.6 (280 ratings) — better
Positive reviews60.0% of reviews78.7% of reviews — better
Number of ratings—280 — better
Update frequencyEvery 3 monthsEvery 3 months
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.012.0 — better
Further details — not scored
Size76 MB19 MB
Age rating4+4+
DeveloperLD DIDACTIC GmbHRWTH Aachen University

Customer experience

CASSY App

Written reviews5 reviews
Positive60.0%
Neutral0.0%
Negative40.0%

phyphox

All ratings276 ratings
Positive89.5%
Neutral4.0%
Negative6.5%
Written reviews267 reviews
Positive78.7%
Neutral3.4%
Negative18.0%

Bugs and requests

CASSY App

Not enough reviews yet to summarise bugs or requests.

phyphox

Reported bugs

21 issues
  • App crashes on older devices
  • Barometer not working on iOS 17.4
  • Network error: Generic error
  • Sound measurement curve disappears
  • App crashes frequently
Show 16 more
  • Cannot be opened on iPhone 6
  • Light sensor not implemented
  • Recording stops when phone is locked or app is minimized
  • Green lines on screen and faded to black after using barometer sensor
  • WLAN not working after using the app
  • Pressure no longer displayed on iOS 17.5
  • Barometer not working on iOS 17.4
  • Latest version cannot be opened on iPhone 6
  • Sound chronometer reset button not working
  • iPad destroyed after update
  • App displays Russian language by default
  • Experiments not working on iPhone 7
  • Magnetometer not working after update on iPhone 5s
  • GPS shows 0 satellites with 6m accuracy
  • App claims iPhone 11 is comparable to a low-cost tablet
  • App crashes every time

Requested features

33 requests
  • Add infrasound detector
  • More units of measurement (G-force, PSI, feet)
  • NFC/RFID support
  • In-app bug report feature
  • Allow other sensors via USB-C
Show 28 more
  • Ability to plug in external sensors
  • Slo-mo recording with timestamps
  • Add attitude sensor (roll, pitch, yaw)
  • Integration with Apple Shortcuts
  • Ability to record audio/dB simultaneously with other sensors
  • Adjustable sampling frequency for all sensors
  • Dark mode option
  • Experiment editor integrated into the app
  • More documentation for the editor
  • Ability to form averages
  • Support for older iPhones (iPhone 6)
  • Add GPS satellite count display
  • Add speedometer functionality
  • Add Lux measurement using light sensor/camera
  • Ability to play recorded audio
  • Limit input for sound analyzers (dB/Hz range)
  • Wi-Fi and RF module access for EMF analysis
  • iWatch integration
  • Improve audio generator capability
  • Allow background/screen locked recording
  • Add light sensor functionality
  • Change units of measurement
  • Add more precise measurements for static cases
  • Add FFT and spectral generation for accelerometer
  • Support for older devices
  • Improve UI/UX for new users
  • Add support for more languages
  • Add a donate option

In-app purchases

None

CASSY App

No in-app purchases

None

phyphox

No in-app purchases

Questions

Is CASSY App free?
CASSY App is free to download, with no in-app purchases.
Is phyphox free?
phyphox is free to download, with no in-app purchases.
Do CASSY App or phyphox have ads?
Neither CASSY App nor phyphox shows ads.
Which is updated more often, CASSY App or phyphox?
CASSY App ships an update every 3 months, and phyphox every 3 months. Most recently, CASSY App was updated on October 24, 2026 and phyphox on October 24, 2026.

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