# O vs Security Photo

The clearest difference is price: O at Free against Security Photo's $0.99. O also leads on in-app purchases (none vs 1) and ads (none vs shown). Security Photo's advantage is update cadence (every 3 months vs every 11 months) and device support (3 vs 1).

O is free to download; Security Photo costs $0.99 up front. Security Photo sells 1 one-off in-app purchase. O asks for nothing beyond the download.

O ships an update every 11 months, Security Photo every 3 months. The most recent releases landed on October 12, 2026 and September 30, 2026 respectively.

## The numbers

| Metric | O | Security Photo |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/o-ring-master/id1072051820/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 11 months | **Every 3 months** |
| Monetization | Free | — |
| Size | 47 MB | 21 MB |
| Requires iOS | 16.0 | **12.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [GE MAO RUBBER INDUSTRIAL CO., LTD.](https://appshunter.io/developer/1078558543) | [少泽 梁](https://appshunter.io/developer/897112791) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-ring-master/id1072051820)

This app provides a comprehensive offline tool for selecting standard rubber seal sizes, including O-Rings, X-Rings, and Back-Up Rings. It offers dimension searches, housing calculations for various sealing applications, and supports multiple international standards in both metric and imperial units.

**Highlights:** Offline standard rubber seal size selection, Search for O-Ring, X-Ring, and Back-Up Ring sizes, O-Ring housing calculations for sealing applications, Supports multiple international standards (AS568, METRIC, JIS, etc.), Metric and Imperial unit support, Substitutable O-Ring size suggestions

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

**In-app purchases:** none


### Security Photo

[App page](https://appshunter.io/ios/app/security-photo/id1447210330)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Upgrade To Pro | $1.99 | one-time |


## Frequently asked questions

### Is O free?

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

### Is Security Photo free?

Security Photo costs $0.99, and also offers in-app purchases.

### Do O or Security Photo have ads?

Security Photo shows ads; O does not.

### Which is updated more often, O or Security Photo?

O ships an update every 11 months, and Security Photo every 3 months. Most recently, O was updated on October 12, 2026 and Security Photo on September 30, 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.*