# SimpleFFT vs Ka

The clearest difference is in-app purchases: Ka at none against SimpleFFT's 1. Ka also leads on ads (none vs shown) and update cadence (every 2 months 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. Ka asks for nothing beyond the download.

SimpleFFT ships an update every 18 months, Ka every 2 months. The most recent releases landed on October 10, 2026 and October 3, 2026 respectively.

## The numbers

| Metric | SimpleFFT | Ka |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 18 months | **Every 2 months** |
| Size | 5 MB | 30 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [HIROFUMI MARUO](https://appshunter.io/developer/667820705) | [Ka-ching ApS](https://appshunter.io/developer/1474762453) |

## 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 |


### Ka

[App page](https://appshunter.io/ios/app/ka-ching-secondscreen/id1474762949)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SimpleFFT free?

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

### Is Ka free?

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

### Do SimpleFFT or Ka have ads?

SimpleFFT shows ads; Ka does not.

### Which is updated more often, SimpleFFT or Ka?

SimpleFFT ships an update every 18 months, and Ka every 2 months. Most recently, SimpleFFT was updated on October 10, 2026 and Ka on October 3, 2026.

---

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