# Orifice Flow Rate Calculator vs OPTIC Mobile (Friendly Eagle)

The clearest difference is update cadence: OPTIC Mobile (Friendly Eagle) at every 3 weeks against Orifice Flow Rate Calculator's every 6 months. OPTIC Mobile (Friendly Eagle) also leads on iOS requirement (12.2 vs 15.6). Orifice Flow Rate Calculator's advantage is ratings volume (98 vs 1). On price, rating, ads and in-app purchases there is nothing between them.

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

On the App Store both sit at effectively the same score — 4.9 for Orifice Flow Rate Calculator against 5.0 for OPTIC Mobile (Friendly Eagle). That said, the two scores are not equally well evidenced: Orifice Flow Rate Calculator has 98 ratings behind it against 1, so its average is the more settled of the two.

Orifice Flow Rate Calculator ships an update every 6 months, OPTIC Mobile (Friendly Eagle) every 3 weeks. The most recent releases landed on September 7, 2026 and September 8, 2026 respectively.

## The numbers

| Metric | Orifice Flow Rate Calculator | OPTIC Mobile (Friendly Eagle) |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.9 (98 ratings)](https://appshunter.io/ios/app/orifice-flow-rate-calculator/id1439701941/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/optic-mobile-friendly-eagle/id1459160092/reviews)** |
| Number of ratings | **98** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 2 MB | 70 MB |
| Requires iOS | 15.6 | **12.2** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [R.L. Laughlin & Company, Inc.](https://appshunter.io/developer/1438670681) | [FRIENDLY EAGLE SOFTWARE INC.](https://appshunter.io/developer/1459160091) |

## What reviewers say

### Orifice Flow Rate Calculator

[App page](https://appshunter.io/ios/app/orifice-flow-rate-calculator/id1439701941)

Easily calculate natural gas orifice flow rates using the AGA 3 standard. This utility app allows users to determine MCF production for a given duration, save calculations, and export data to CSV. It functions offline, requiring no cell service.

**Highlights:** Orifice MCF Calculator, Rotary (Direct) MCF Calculator, Save all calculations, View saved inputs and calculations, Export calculations to CSV

**Features:** macOS Compatibility

**In-app purchases:** none


### OPTIC Mobile (Friendly Eagle)

[App page](https://appshunter.io/ios/app/optic-mobile-friendly-eagle/id1459160092)

Access and modify records from the OPTIC server on your mobile device. Create, delete, and update entries, with offline capabilities for data and documents. Sync changes back to the server when connected.

**Highlights:** View and update server records, Create and delete new records, Offline data access and saving, Downloadable documents and SDS, Customizable download settings, Syncs with OPTIC Web application

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

**In-app purchases:** none


## Frequently asked questions

### Is Orifice Flow Rate Calculator free?

Orifice Flow Rate Calculator is free to download, with no in-app purchases.

### Is OPTIC Mobile (Friendly Eagle) free?

OPTIC Mobile (Friendly Eagle) is free to download, with no in-app purchases.

### Which has better reviews, Orifice Flow Rate Calculator or OPTIC Mobile (Friendly Eagle)?

OPTIC Mobile (Friendly Eagle) is rated higher. Orifice Flow Rate Calculator averages 4.9 out of 5 from 98 ratings, while OPTIC Mobile (Friendly Eagle) averages 5.0 from 1 ratings.

### Do Orifice Flow Rate Calculator or OPTIC Mobile (Friendly Eagle) have ads?

Neither Orifice Flow Rate Calculator nor OPTIC Mobile (Friendly Eagle) shows ads.

### Which is updated more often, Orifice Flow Rate Calculator or OPTIC Mobile (Friendly Eagle)?

Orifice Flow Rate Calculator ships an update every 6 months, and OPTIC Mobile (Friendly Eagle) every 3 weeks. Most recently, Orifice Flow Rate Calculator was updated on September 7, 2026 and OPTIC Mobile (Friendly Eagle) on September 8, 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.*