# O vs Metal +

The clearest difference is in-app purchases: O at none against Metal +'s 1. Metal +'s advantage is update cadence (every 4 months vs every 18 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Metal + sells 1 one-off in-app purchase. O asks for nothing beyond the download.

O ships an update every 18 months, Metal + every 4 months. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | O | Metal + |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.8 (12 ratings)](https://appshunter.io/ios/app/metal-plus/id6446039096/reviews)** |
| Number of ratings | — | **12** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 18 months | **Every 4 months** |
| Monetization | — | Free with in-app purchases |
| Size | 16 MB | 5 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [HUTCHINSON](https://appshunter.io/developer/862345826) | [Mohamed Saad](https://appshunter.io/developer/1291109619) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-ring-info/id1369062925)

**Features:** macOS Compatibility

**In-app purchases:** none


### Metal +

[App page](https://appshunter.io/ios/app/metal-plus/id6446039096)

Easily calculate the weight and price of various metal forms and alloys. Save your projects and access calculations offline. This tool supports multiple units and metal types for precise results.

**Highlights:** Calculate weight of round, sheet, tube, rectangle forms, Supports steel, aluminum, nickel, copper, gold, silver alloys, Calculate paint surface area, Weight converter, Price per kilogram/ton converter, Save items and projects, Offline functionality

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads | $4.99 | one-time |


## Frequently asked questions

### Is O free?

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

### Is Metal + free?

Metal + is free to download, with in-app purchases available.

### Do O or Metal + have ads?

Neither O nor Metal + shows ads.

### Which is updated more often, O or Metal +?

O ships an update every 18 months, and Metal + every 4 months. Most recently, O was updated on October 26, 2026 and Metal + on October 24, 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.*