Voice Spectrogram Logger vs Percentile Test Prep
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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
Percentile Test Prep
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Get Personalized Learning Outcomes for everyone. An in-depth performance analysis, where you can know your strong and weak points, your all India rank, your state rank etc. You will also get a virtual tutor who is completely dedicated to bringing out the best in you. It will prioritize your concepts, chapters, topics, and questions through machine learning. Get this innovative learning experience only on Percentile Test Prep Test Series!!
Screenshots
Verdict
Voice Spectrogram Logger and Percentile Test Prep are too close to call on the numbers: across 6 compared parameters — price, update cadence, ads and in-app purchases among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
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. Voice Spectrogram Logger sells 1 one-off in-app purchase and Percentile Test Prep sells 10 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.
Voice Spectrogram Logger ships an update every 15 months, Percentile Test Prep every 8 months. The most recent releases landed on July 29, 2026 and September 8, 2026 respectively.
| Parameter | Voice Spectrogram Logger | Percentile Test Prep |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) — better | — |
| Positive reviews | 0.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 15 months | Every 8 months — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.5 | 15.5 |
| Further details — not scored | ||
| Size | 7 MB | 147 MB |
| Age rating | 12+ | 4+ |
| Developer | Yukiko Iwai | Online Learning |
In-app purchases
Voice Spectrogram Logger
- Remove Ads$3.99
Percentile Test Prep
- Package - AV$34.99
- Package - AX$39.99
- Package - BD$39.99
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- Package - AY$39.99
- Package - BC$39.99
- Package - BB$39.99
- Package - BE$44.99
- Package - BF$49.99
- Package - BH$49.99
- Package - BG$49.99
Questions
Is Voice Spectrogram Logger free?
Is Percentile Test Prep free?
Do Voice Spectrogram Logger or Percentile Test Prep have ads?
Which is updated more often, Voice Spectrogram Logger or Percentile Test Prep?
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