# Optical Surface Recognition vs Sentient Spire

The clearest difference is update cadence: Sentient Spire at every 4 days against Optical Surface Recognition's every 2 weeks. Optical Surface Recognition's advantage is iOS requirement (12.0 vs 15.1). On price, ads, in-app purchases and device support there is nothing between them.

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

Optical Surface Recognition ships an update every 2 weeks, Sentient Spire every 4 days. The most recent releases landed on October 7, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Optical Surface Recognition | Sentient Spire |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/optical-surface-recognition/id1480828202/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 4 days** |
| Monetization | Free | — |
| Size | 17 MB | 44 MB |
| Requires iOS | **12.0** | 15.1 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Engineering Director, Inc.](https://appshunter.io/developer/1480828201) | [XYBERTEQ INNOVATIONS SDN. BHD.](https://appshunter.io/developer/1850281779) |

## What reviewers say

### Optical Surface Recognition

[App page](https://appshunter.io/ios/app/optical-surface-recognition/id1480828202)

This utility app uses computer vision to scan surfaces for signs of corrosion on various metal types. It allows users to capture photos and record videos of detected corrosion, saving them with a proprietary score.

**Highlights:** Detects corrosion on various metal surfaces, Scans flat metal, nails, bolts, signs, poles, grates, Captures photos with corrosion score, Records videos with corrosion score, Saves media to device photo roll

**Features:** macOS Compatibility

**In-app purchases:** none


### Sentient Spire

[App page](https://appshunter.io/ios/app/sentient-spire-mobile-defense/id6761624367)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Optical Surface Recognition free?

Optical Surface Recognition is free to download, with no in-app purchases.

### Is Sentient Spire free?

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

### Do Optical Surface Recognition or Sentient Spire have ads?

Neither Optical Surface Recognition nor Sentient Spire shows ads.

### Which is updated more often, Optical Surface Recognition or Sentient Spire?

Optical Surface Recognition ships an update every 2 weeks, and Sentient Spire every 4 days. Most recently, Optical Surface Recognition was updated on October 7, 2026 and Sentient Spire on October 25, 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.*