# BTワットチェッカー vs Audio SA

The clearest difference is review sentiment: Audio SA at 100% against BTワットチェッカー's 36%. BTワットチェッカー's advantage is in-app purchases (none vs 1) and ads (none vs shown). On price, update cadence, device support and iOS requirement there is nothing between them.

Both are free to download. Audio SA sells 1 one-off in-app purchase. BTワットチェッカー asks for nothing beyond the download.

BTワットチェッカー ships an update every 3 months, Audio SA every 6 months. The most recent releases landed on October 25, 2026 and October 27, 2026 respectively.

## The numbers

| Metric | BTワットチェッカー | Audio SA |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 35.7% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 3 months** | Every 6 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 3 MB | 5 MB |
| Requires iOS | 15.6 | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [RATOC Systems, Inc.](https://appshunter.io/developer/568725272) | [Yasuyoshi Ota](https://appshunter.io/developer/1500357652) |

## What reviewers say

### BTワットチェッカー

[App page](https://appshunter.io/ios/app/bt/id1490362165)

Monitor and control power consumption with real-time data visualization. Convert energy usage into electricity costs and CO2 emissions, with historical data presented in graphs. Save measurement data to CSV files and remotely manage power ON/OFF.

**Highlights:** Real-time power, current, and voltage display, Convert energy usage to cost and CO2 emissions, Historical data in bar graphs (hourly, daily, monthly, yearly), Save measurement data to CSV, Remote power ON/OFF control

**Features:** macOS Compatibility

**In-app purchases:** none


### 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 |


## Frequently asked questions

### Is BTワットチェッカー free?

BTワットチェッカー is free to download, with no in-app purchases.

### Is Audio SA free?

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

### Do BTワットチェッカー or Audio SA have ads?

Audio SA shows ads; BTワットチェッカー does not.

### Which is updated more often, BTワットチェッカー or Audio SA?

BTワットチェッカー ships an update every 3 months, and Audio SA every 6 months. Most recently, BTワットチェッカー was updated on October 25, 2026 and Audio SA on October 27, 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.*