# Keystone Correction vs Roulette

The clearest difference is iOS requirement: Keystone Correction at 11.0 against Roulette's 13.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Keystone Correction ships an update every 2 months, Roulette daily. The most recent releases landed on September 16, 2026 and September 18, 2026 respectively.

## The numbers

| Metric | Keystone Correction | Roulette |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (5 ratings)](https://appshunter.io/ios/app/keystone-correction-comcam/id1504346555/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | 66.7% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | Yes |
| Update frequency | Every 2 months | **Daily** |
| Monetization | Ad-supported | — |
| Size | 19 MB | 172 MB |
| Requires iOS | **11.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Masayoshi Shibata](https://appshunter.io/developer/1474388626) | [Katsunori Sasamoto](https://appshunter.io/developer/1526457267) |

## What reviewers say

### Keystone Correction

[App page](https://appshunter.io/ios/app/keystone-correction-comcam/id1504346555)

Easily scan and auto-correct documents directly on your device. This secure app keeps your images private by not uploading them online, making it ideal for sensitive business use. All functions are available for free, with no registration or complicated steps required.

**Highlights:** Automatic keystone correction, Secure offline processing, Easy document digitization, Free to use all functions, No user registration, Simple interface

**In-app purchases:** none


### Roulette

[App page](https://appshunter.io/ios/app/roulette-gggsoft/id6740266274)

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

**In-app purchases:** none


## Frequently asked questions

### Is Keystone Correction free?

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

### Is Roulette free?

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

### Do Keystone Correction or Roulette have ads?

Both Keystone Correction and Roulette show ads.

### Which is updated more often, Keystone Correction or Roulette?

Keystone Correction ships an update every 2 months, and Roulette daily. Most recently, Keystone Correction was updated on September 16, 2026 and Roulette on September 18, 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.*