# Proof Authentication vs Card Centering Calculator

The clearest difference is in-app purchases: Proof Authentication at none against Card Centering Calculator's 2. Proof Authentication also leads on review sentiment (50% vs 40%). Card Centering Calculator's advantage is update cadence (every 2 weeks vs every 2 months) and ratings volume (55 vs 7). On price, rating, ads and device support there is nothing between them.

Both are free to download. Card Centering Calculator sells 2 in-app purchases, starting at $2.99 per 7 days. Proof Authentication asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 4.4 for Proof Authentication against 4.3 for Card Centering Calculator. That said, the two scores are not equally well evidenced: Card Centering Calculator has 55 ratings behind it against 7, so its average is the more settled of the two. Written reviews are what separate them: 50% of Proof Authentication's written reviews are positive against 40% of Card Centering Calculator's.

Proof Authentication ships an update every 2 months, Card Centering Calculator every 2 weeks. The most recent releases landed on September 8, 2026 and September 13, 2026 respectively.

## The numbers

| Metric | Proof Authentication | Card Centering Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (7 ratings)](https://appshunter.io/ios/app/proof-authentication/id1589988080/reviews)** | [4.3 (55 ratings)](https://appshunter.io/ios/app/card-centering-calculator-ccc/id6745336791/reviews) |
| Number of ratings | 7 | **55** |
| Positive reviews | **50.0% of reviews** | 40.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 2 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 76 MB | 18 MB |
| Requires iOS | **14.4** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Proof Authentication Corporation](https://appshunter.io/developer/1604240795) | [Arda Sen](https://appshunter.io/developer/1670665250) |

## What reviewers say

### Proof Authentication

[App page](https://appshunter.io/ios/app/proof-authentication/id1589988080)

Verify product authenticity instantly by scanning official security marks. Ensure your purchases are genuine with rapid and accurate authentication. Look for the Proof Security Mark on select consumer goods.

**Highlights:** Instant product authentication, Scan Official Proof Security Marks, High accuracy verification, Fast results, Supports selected consumer items

**In-app purchases:** none


### Card Centering Calculator

[App page](https://appshunter.io/ios/app/card-centering-calculator-ccc/id6745336791)

This app helps trading card collectors accurately measure card centering for professional grading. It offers automatic border detection with manual adjustments, clear measurement results, and the ability to compare potential grades across major companies. Save and manage your analyzed cards to stop guessing and start measuring.

**Highlights:** Accurate centering measurements, Automatic border detection, Manual guide adjustments, Compare potential grades, Save and manage analyzed cards, Image import via camera or photos

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Weekly Subscription | $2.99 | per 7 days |
| Yearly Subscription | $19.99 | per year |


## Frequently asked questions

### Is Proof Authentication free?

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

### Is Card Centering Calculator free?

Card Centering Calculator is free to download, with in-app purchases available.

### Which has better reviews, Proof Authentication or Card Centering Calculator?

Proof Authentication is rated higher. Proof Authentication averages 4.4 out of 5 from 7 ratings, while Card Centering Calculator averages 4.3 from 55 ratings.

### Do Proof Authentication or Card Centering Calculator have ads?

Neither Proof Authentication nor Card Centering Calculator shows ads.

### Which is updated more often, Proof Authentication or Card Centering Calculator?

Proof Authentication ships an update every 2 months, and Card Centering Calculator every 2 weeks. Most recently, Proof Authentication was updated on September 8, 2026 and Card Centering Calculator on September 13, 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.*