Comparison

phyphox vs Voice Spectrogram Logger

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

Head to head
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.

About

Voice Spectrogram Logger

Visualize voice frequencies in a spectrogram from 20-2500Hz. Adjust display with sliders and log recordings to export as PNG files. Functions fully offline and supports background processing.

Highlights
  • Real-time voice spectrogram display
  • Adjustable frequency range (20-2500Hz)
  • Zoomable spectrogram with pinch gestures
  • Customizable spectrogram gradation
  • Logging mode with history export
  • Offline functionality
Features
Read full description

1. DESPLAY The spectrogram of voice is displayed in the range of 20 - 2500Hz. You can zoom in/out the spectrogram by pinching in/out smoothly. Also landscape orientation is supported. 2. USEFUL By moving "vivid" slider, the gradation of spectrogram is controlled. The gradation is also controlled by moving "baseline" slider in "Setting" tab and selecting "Mean" or "RMS" as the way of smoothing the spectrogram out. 3. LOGGING When "log" switch is ON, this app runs in the logging mode. To choose a past log from "History" tab, you can pull it from iPhone via email as a PNG file. 4. AVAILABLE Without cellular data service, the full functions are available. The background processing is supported. 5. TECHNICAL NOTE Sample rate: 44.1kHz Bit depth: 32bit float FFT window function: Blackman FFT samples: 4096

Screenshots

phyphox4 screens
Voice Spectrogram Logger4 screens

Verdict

The call

The clearest difference is review sentiment: phyphox at 79% against Voice Spectrogram Logger's 0%. phyphox also leads on rating (4.6 vs 1.0) and in-app purchases (none vs 1). On price, ads, monetization model 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. Voice Spectrogram Logger sells 1 one-off in-app purchase. phyphox asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

phyphox holds the better App Store score, 4.6 against 1.0. That said, the two scores are not equally well evidenced: phyphox has 276 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 79% of phyphox's written reviews are positive against 0% of Voice Spectrogram Logger's.

UpkeepUpdate frequency

phyphox ships an update every 3 months, Voice Spectrogram Logger every 15 months. The most recent releases landed on October 12, 2026 and October 2, 2026 respectively.

Scorecard6 real differences · 4 level
phyphox versus Voice Spectrogram Logger: the parameters behind the verdict, then further details
ParameterphyphoxVoice Spectrogram Logger
PriceFreeFree
Rating4.6 (276 ratings) — better1.0 (1 ratings)
Positive reviews78.7% of reviews — better0.0% of reviews
Number of ratings276 — better1
Update frequencyEvery 3 months — betterEvery 15 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better15.5
Further details — not scored
Size19 MB7 MB
Age rating4+12+
DeveloperRWTH Aachen UniversityYukiko Iwai

Customer experience

phyphox

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

Voice Spectrogram Logger

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Bugs and 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

Voice Spectrogram Logger

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

phyphox

No in-app purchases

1 purchases

Voice Spectrogram Logger

One-time1
  • Remove Ads$3.99

Questions

Is phyphox free?
phyphox is free to download, with no in-app purchases.
Is Voice Spectrogram Logger free?
Voice Spectrogram Logger is free to download, with in-app purchases available.
Which has better reviews, phyphox or Voice Spectrogram Logger?
phyphox is rated higher. phyphox averages 4.6 out of 5 from 276 ratings, while Voice Spectrogram Logger averages 1.0 from 1 ratings.
Do phyphox or Voice Spectrogram Logger have ads?
Neither phyphox nor Voice Spectrogram Logger shows ads.
Which is updated more often, phyphox or Voice Spectrogram Logger?
phyphox ships an update every 3 months, and Voice Spectrogram Logger every 15 months. Most recently, phyphox was updated on October 12, 2026 and Voice Spectrogram Logger on October 2, 2026.

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