# Proof Authentication vs Card Centering Calculator

The clearest difference is in-app purchases: Proof Authentication at none against Card Centering Calculator's 5. Proof Authentication also leads on ads (none vs shown) and iOS requirement (14.4 vs 18.0). Card Centering Calculator's advantage is ratings volume (2.3K vs 7) and rating (4.7 vs 4.4). On price and device support there is nothing between them.

Both are free to download. Card Centering Calculator sells 5 one-off in-app purchases. Proof Authentication asks for nothing beyond the download.

Card Centering Calculator holds the better App Store score, 4.7 against 4.4. That said, the two scores are not equally well evidenced: Card Centering Calculator has 2.3K ratings behind it against 7, so its average is the more settled of the two. Written reviews point the same way: 50% of Proof Authentication's written reviews are positive against 60% of Card Centering Calculator's.

Proof Authentication ships an update every 2 months, Card Centering Calculator every 3 weeks. The most recent releases landed on September 8, 2026 and September 29, 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) | **[4.7 (2.3K ratings)](https://appshunter.io/ios/app/card-centering-calculator/id6661022837/reviews)** |
| Number of ratings | 7 | **2.3K** |
| Positive reviews | 50.0% of reviews | **60.5% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 76 MB | 18 MB |
| Requires iOS | **14.4** | 18.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | +4 |
| Developer | [Proof Authentication Corporation](https://appshunter.io/developer/1604240795) | [Jade Lizard Software LLC](https://appshunter.io/developer/528029155) |

## 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/id6661022837)

This app helps collectors and traders measure card centering ratios for grading. It uses AI to detect centering or allows manual adjustments for precise measurements, displaying potential grades from major companies.

**Highlights:** AI-powered card centering detection, Manual centering measurement with zoom, Grade comparisons for PSA, BGS, SGC, CGC, TAG, ACE, Front and back side centering measurement, Grading standards reference guide, Off-center visualization tool

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Small Tip | $0.99 | one-time |
| Medium Tip | $1.99 | one-time |
| Unlock Premium | $4.99 | one-time |
| Large Tip | $4.99 | one-time |
| Pristine Tip | $9.99 | one-time |

**What reviewers like**

- 👍 Intuitive and flexible
- 🚀 Provides great information on centering
- 💡 Helpful for graders and collectors
- 👍 Easy to use and user-friendly
- 👍 Accurate and works as a physical tool

**What reviewers complain about**

- 🐛 Centering measurement doesn't work properly
- 🔒 Grading information locked behind paywall
- 🐛 Camera quality issues, app resets during use

**Reported bugs**

- Centering measurement resets during use
- Image rotation doesn't stay in place

**Requested features**

- Thinner and dashed centering lines for better visibility
- Free access to grading information without subscription


## 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?

Card Centering Calculator is rated higher. Proof Authentication averages 4.4 out of 5 from 7 ratings, while Card Centering Calculator averages 4.7 from 2.3K ratings.

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

Card Centering Calculator shows ads; Proof Authentication does not.

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

Proof Authentication ships an update every 2 months, and Card Centering Calculator every 3 weeks. Most recently, Proof Authentication was updated on September 8, 2026 and Card Centering Calculator on September 29, 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.*