# SimpleFFT vs DiagPro+

The clearest difference is in-app purchases: DiagPro+ at none against SimpleFFT's 1. DiagPro+ also leads on ads (none vs shown) and update cadence (monthly vs every 18 months). On price, device support and iOS requirement there is nothing between them.

Both are free to download. SimpleFFT sells 1 one-off in-app purchase. DiagPro+ asks for nothing beyond the download.

SimpleFFT ships an update every 18 months, DiagPro+ monthly. The most recent releases landed on August 28, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | SimpleFFT | DiagPro+ |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 18 months | **Monthly** |
| Size | 5 MB | 30 MB |
| Requires iOS | **15.0** | 15.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [HIROFUMI MARUO](https://appshunter.io/developer/667820705) | [FIELDS-IQ LLC](https://appshunter.io/developer/1884210066) |

## What reviewers say

### SimpleFFT

[App page](https://appshunter.io/ios/app/simplefft/id1239257017)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Functions | $0.49 | one-time |


### DiagPro+

[App page](https://appshunter.io/ios/app/diagpro-plus/id6760949575)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SimpleFFT free?

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

### Is DiagPro+ free?

DiagPro+ is free to download, with no in-app purchases.

### Do SimpleFFT or DiagPro+ have ads?

SimpleFFT shows ads; DiagPro+ does not.

### Which is updated more often, SimpleFFT or DiagPro+?

SimpleFFT ships an update every 18 months, and DiagPro+ monthly. Most recently, SimpleFFT was updated on August 28, 2026 and DiagPro+ on September 21, 2026.

---

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