# O vs Pneumatics

The clearest difference is review sentiment: O at 83% against Pneumatics's 0%. O also leads on iOS requirement (12.1 vs 17.0). Pneumatics's advantage is update cadence (monthly vs every 3 months). On price, ads, in-app purchases and monetization model there is nothing between them.

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

O ships an update every 3 months, Pneumatics monthly. The most recent releases landed on September 30, 2026 and October 2, 2026 respectively.

## The numbers

| Metric | O | Pneumatics |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.8 (5 ratings)](https://appshunter.io/ios/app/o-ring/id485346224/reviews)** | — |
| Number of ratings | **5** | — |
| Positive reviews | **83.3% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Monthly** |
| Monetization | Free | Free |
| Size | 26 MB | 4 MB |
| Requires iOS | **12.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) | [Amnaj Sriwilai](https://appshunter.io/developer/1241468165) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-ring/id485346224)

This app helps users calculate O-Ring dimensions and find compatible materials for their applications. It provides recommendations based on ISO standards and supports both metric and inch measurements.

**Highlights:** O-Ring housing calculation, O-Ring size recommendations by ISO standard, Quick search by national/international standards, O-Ring tolerance calculation, Metric and inch unit switching, Chemical compatibility check, Integration of Trelleborg Sealing Solutions Videos

**Features:** macOS Compatibility

**In-app purchases:** none


### Pneumatics

[App page](https://appshunter.io/ios/app/pneumatics/id1241653182)

This app offers essential calculation tools for pneumatic systems, aiding in automation system design and equipment selection. It helps users determine cylinder force, speed, air consumption, and estimate costs, streamlining work with pneumatic components.

**Highlights:** Cylinder force calculation, Force requirement estimation, Cylinder speed calculation, Air consumption calculation, Shock absorber analysis, Pressure and flow rate conversion, Hose diameter and piston rod diameter definition

**In-app purchases:** none


## Frequently asked questions

### Is O free?

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

### Is Pneumatics free?

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

### Do O or Pneumatics have ads?

Neither O nor Pneumatics shows ads.

### Which is updated more often, O or Pneumatics?

O ships an update every 3 months, and Pneumatics monthly. Most recently, O was updated on September 30, 2026 and Pneumatics on October 2, 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.*