# Correctional Services Bureau vs KOI Keyboard

The clearest difference is in-app purchases: Correctional Services Bureau at none against KOI Keyboard's 10. Correctional Services Bureau also leads on device support (3 vs 1). KOI Keyboard's advantage is update cadence (every 4 days vs every 5 months). On price, ads and iOS requirement there is nothing between them.

Both are free to download. KOI Keyboard sells 10 one-off in-app purchases. Correctional Services Bureau asks for nothing beyond the download.

Correctional Services Bureau ships an update every 5 months, KOI Keyboard every 4 days. The most recent releases landed on October 24, 2026 and November 6, 2026 respectively.

## The numbers

| Metric | Correctional Services Bureau | KOI Keyboard |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 4 days** |
| Size | 13 MB | 363 MB |
| Requires iOS | **15.6** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Correctional Services Bureau](https://appshunter.io/developer/1228513133) | [Chi Yu Cheng](https://appshunter.io/developer/1896654870) |

## What reviewers say

### Correctional Services Bureau

[App page](https://appshunter.io/ios/app/correctional-services-bureau/id1228513134)

**Features:** macOS Compatibility

**In-app purchases:** none


### KOI Keyboard

[App page](https://appshunter.io/ios/app/koi-keyboard/id6789937180)

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

**In-app purchases (10)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 精鑄銀 | $0.99 | one-time |
| 霜晶 | $0.99 | one-time |
| 織絹 | $0.99 | one-time |
| 隱翹・霓主題 | $0.99 | one-time |
| 紙墨 | $1.99 | one-time |
| 櫻桃軟糖 | $1.99 | one-time |
| 橙潮掌機 | $1.99 | one-time |
| 午夜爵士 | $1.99 | one-time |
| 青釉 | $1.99 | one-time |
| KOI Keyboard Sizing | $1.99 | one-time |


## Frequently asked questions

### Is Correctional Services Bureau free?

Correctional Services Bureau is free to download, with no in-app purchases.

### Is KOI Keyboard free?

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

### Do Correctional Services Bureau or KOI Keyboard have ads?

Neither Correctional Services Bureau nor KOI Keyboard shows ads.

### Which is updated more often, Correctional Services Bureau or KOI Keyboard?

Correctional Services Bureau ships an update every 5 months, and KOI Keyboard every 4 days. Most recently, Correctional Services Bureau was updated on October 24, 2026 and KOI Keyboard on November 6, 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.*