# Audio SA vs OTA Tools

The clearest difference is in-app purchases: OTA Tools at none against Audio SA's 1. OTA Tools also leads on ads (none vs shown). Audio SA's advantage is update cadence (every 6 months vs every 13 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Audio SA sells 1 one-off in-app purchase. OTA Tools asks for nothing beyond the download.

Audio SA ships an update every 6 months, OTA Tools every 13 months. The most recent releases landed on August 31, 2026 and August 12, 2026 respectively.

## The numbers

| Metric | Audio SA | OTA Tools |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 6 months** | Every 13 months |
| Monetization | Free with in-app purchases | — |
| Size | 5 MB | 27 MB |
| Requires iOS | 15.6 | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) | [Fitshow (Xiamen) Infomation Technology Co., Ltd.](https://appshunter.io/developer/1099080594) |

## What reviewers say

### Audio SA

[App page](https://appshunter.io/ios/app/audio-sa/id6444715596)

This app analyzes audio waveforms to create visual voiceprints as TFFT images. It offers extensive customization for FFT analysis, including adjustable ranges, sizes, scales, and window functions. A simple waveform generator is also included for learning purposes.

**Highlights:** TFFT voiceprint image generation, High-resolution image export, Customizable FFT analysis settings, Adjustable audio waveform analysis range, Simple waveform generator (sine, square, noise), Multiple FFT sizes and window functions

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove ads. | $3.99 | one-time |


### OTA Tools

[App page](https://appshunter.io/ios/app/ota-tools-treadmill/id6470582822)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Audio SA free?

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

### Is OTA Tools free?

OTA Tools is free to download, with no in-app purchases.

### Do Audio SA or OTA Tools have ads?

Audio SA shows ads; OTA Tools does not.

### Which is updated more often, Audio SA or OTA Tools?

Audio SA ships an update every 6 months, and OTA Tools every 13 months. Most recently, Audio SA was updated on August 31, 2026 and OTA Tools on August 12, 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.*