Keystone Correction vs Roulette
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Keystone Correction
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.
- Automatic keystone correction
- Secure offline processing
- Easy document digitization
- Free to use all functions
- No user registration
- Simple interface
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* [Easy] scan and auto-correction * [Secure] don't upload images to the Internet. * [Free] free for all functions. Comcam is a simple, secure, and powerful scanner App ## how to use Step 1: Take a photo or load an existing photo Step2. cut out the part you want Step3. save to a photo app or share to another app ## features - Since the captured images are not uploaded to the Internet, you can be used for business without worrying about security. - Paper documents can be easily digitized, making it possible to go paperless with little effort. - There are no complicated functions, so anyone can use it easily. - Use all features for free. - No user registration required. - No need to upload images to the Internet.
Roulette
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*Supported languages English/Japanese This is an app that allows you to create roulette and notes. 〇 Auto-generate roulette You can generate a roulette from the notes you create. Roulette items are separated by commas, newlines, or spaces. 〇 Overlap You can stack two roulette wheels. By spinning the stacked roulette wheels, two items will be selected at the same time. 〇 Icon setting You can set an icon for each item. You can choose to display only the icon when spinning the roulette. 〇 Connection By specifying the connection destination for an item, you can immediately call up the connected roulette when you win the roulette. In addition, a function is implemented that automatically generates a roulette consisting only of connection items to the roulette stored in a folder by specifying a folder. 〇 Folder You can save the roulettes and notes you create in separate folders. By specifying a roulette as a favorite, you can instantly store it in the favorites folder. 〇 Sound You can specify background music and sound effects, such as environmental sounds and music. 〇 History When you spin the roulette, a history is saved, and you can check later which items were selected.
Screenshots
Verdict
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.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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.
| Parameter | Keystone Correction | Roulette |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (5 ratings) — better | — |
| Positive reviews | 66.7% of reviews | — |
| Number of ratings | 5 — better | — |
| Update frequency | Every 2 months | Daily — better |
| Ads | Yes | Yes |
| In-app purchases | No | No |
| Monetization | Ad-supported | — |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 11.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 19 MB | 172 MB |
| Age rating | 4+ | 4+ |
| Developer | Masayoshi Shibata | Katsunori Sasamoto |
In-app purchases
Keystone Correction
No in-app purchases
Roulette
No in-app purchases
Questions
Is Keystone Correction free?
Is Roulette free?
Do Keystone Correction or Roulette have ads?
Which is updated more often, Keystone Correction or Roulette?
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