# Audio Frequency Analyzer vs BookListViewer2

The clearest difference is price: BookListViewer2 at Free against Audio Frequency Analyzer's $9.99. BookListViewer2 also leads on update cadence (every 3 months vs every 8 months) and device support (3 vs 1). Audio Frequency Analyzer's advantage is in-app purchases (none vs 1). On ads there is nothing between them.

BookListViewer2 is free to download; Audio Frequency Analyzer costs $9.99 up front. BookListViewer2 sells 1 one-off in-app purchase. Audio Frequency Analyzer asks for nothing beyond the download.

Audio Frequency Analyzer ships an update every 8 months, BookListViewer2 every 3 months. The most recent releases landed on September 9, 2026 and May 17, 2026 respectively.

## The numbers

| Metric | Audio Frequency Analyzer | BookListViewer2 |
| --- | --- | --- |
| Price | $9.99 | **Free** |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/audio-frequency-analyzer/id684641742/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 60.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 3 months** |
| Monetization | Paid | — |
| Size | 0 MB | 11 MB |
| Requires iOS | 26.2 | **12.1** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [TOON,LLC](https://appshunter.io/developer/633948723) | [Mika Hatakeyama](https://appshunter.io/developer/445272831) |

## What reviewers say

### Audio Frequency Analyzer

[App page](https://appshunter.io/ios/app/audio-frequency-analyzer/id684641742)

This real-time audio analyzer measures and evaluates sound environments with 1/3 octave band frequency response and FFT analysis. It supports calibration for high accuracy and is suitable for various audio testing and tuning applications.

**Highlights:** Real-time frequency spectrum response measurement (1/3 octave, 30 bands), FFT Analyzer, Observation frequency range: 20 - 23000 Hz, Calibration function for high accuracy, Supports built-in and external microphones, Snapshot and averaging functions

**In-app purchases:** none


### BookListViewer2

[App page](https://appshunter.io/ios/app/booklistviewer2/id975024899)

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 広告を消す | $0.99 | one-time |


## Frequently asked questions

### Is Audio Frequency Analyzer free?

Audio Frequency Analyzer costs $9.99, with no in-app purchases.

### Is BookListViewer2 free?

BookListViewer2 is free to download, with in-app purchases available.

### Do Audio Frequency Analyzer or BookListViewer2 have ads?

Neither Audio Frequency Analyzer nor BookListViewer2 shows ads.

### Which is updated more often, Audio Frequency Analyzer or BookListViewer2?

Audio Frequency Analyzer ships an update every 8 months, and BookListViewer2 every 3 months. Most recently, Audio Frequency Analyzer was updated on September 9, 2026 and BookListViewer2 on May 17, 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.*