# Keystone Correction vs BulletsMind

The clearest difference is in-app purchases: Keystone Correction at none against BulletsMind's 2. Keystone Correction also leads on iOS requirement (11.0 vs 15.6). BulletsMind's advantage is ads (none vs shown) and review sentiment (100% vs 67%). On price and device support there is nothing between them.

Both are free to download. BulletsMind sells 2 in-app purchases, starting at $1.49 per month. Keystone Correction asks for nothing beyond the download.

Keystone Correction ships an update every 2 months, BulletsMind every 3 weeks. The most recent releases landed on September 16, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | Keystone Correction | BulletsMind |
| --- | --- | --- |
| 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 | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | **Ad-supported** | Freemium |
| Size | 19 MB | 48 MB |
| Requires iOS | **11.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Masayoshi Shibata](https://appshunter.io/developer/1474388626) | [YUKI TANAIKE](https://appshunter.io/developer/478558546) |

## 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


### BulletsMind

[App page](https://appshunter.io/ios/app/bulletsmind-simple-outliner/id1629214528)

This app helps you organize ideas and information using a hierarchical bulleted note system. It combines the usability of mind mapping with outline processing, supporting features like coloring, task management, and link insertion. Export your outlines or sync them across devices.

**Highlights:** Hierarchical bulleted notes, Intuitive operability, Rich expression with coloring, To-do management with progress rates, Link insertion for reference sites, Export and share outlines, Multi-device sync via Google Drive

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| BulletsMind Pro Version Monthly | $1.49 | per month |
| BulletsMind Pro Version Annual | $12.99 | per year |


## Frequently asked questions

### Is Keystone Correction free?

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

### Is BulletsMind free?

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

### Do Keystone Correction or BulletsMind have ads?

Keystone Correction shows ads; BulletsMind does not.

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

Keystone Correction ships an update every 2 months, and BulletsMind every 3 weeks. Most recently, Keystone Correction was updated on September 16, 2026 and BulletsMind on September 17, 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.*