# Voice Spectrogram Logger vs Percentile Test Prep

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.

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.

## The numbers

| Metric | Voice Spectrogram Logger | Percentile Test Prep |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[1.0 (1 ratings)](https://appshunter.io/ios/app/voice-spectrogram-logger/id1277134462/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 15 months | **Every 8 months** |
| Monetization | Free | — |
| Size | 7 MB | 147 MB |
| Requires iOS | 15.5 | 15.5 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Yukiko Iwai](https://appshunter.io/developer/965630131) | [Online Learning](https://appshunter.io/developer/1790866777) |

## What reviewers say

### Voice Spectrogram Logger

[App page](https://appshunter.io/ios/app/voice-spectrogram-logger/id1277134462)

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:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $3.99 | one-time |


### Percentile Test Prep

[App page](https://appshunter.io/ios/app/percentile-test-prep/id6745399523)

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Package - AV | $34.99 | one-time |
| Package - AX | $39.99 | one-time |
| Package - BD | $39.99 | one-time |
| Package - AY | $39.99 | one-time |
| Package - BC | $39.99 | one-time |
| Package - BB | $39.99 | one-time |
| Package - BE | $44.99 | one-time |
| Package - BF | $49.99 | one-time |
| Package - BH | $49.99 | one-time |
| Package - BG | $49.99 | one-time |


## Frequently asked questions

### Is Voice Spectrogram Logger free?

Voice Spectrogram Logger is free to download, with in-app purchases available.

### Is Percentile Test Prep free?

Percentile Test Prep is free to download, with in-app purchases available.

### Do Voice Spectrogram Logger or Percentile Test Prep have ads?

Neither Voice Spectrogram Logger nor Percentile Test Prep shows ads.

### Which is updated more often, Voice Spectrogram Logger or Percentile Test Prep?

Voice Spectrogram Logger ships an update every 15 months, and Percentile Test Prep every 8 months. Most recently, Voice Spectrogram Logger was updated on July 29, 2026 and Percentile Test Prep on September 8, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*