# Flow Test Calculator vs IAAI

The clearest difference is rating: IAAI at 5.0 against Flow Test Calculator's 4.1. IAAI also leads on in-app purchases (none vs 4) and update cadence (every 5 months vs every 90 months). Flow Test Calculator's advantage is ratings volume (63 vs 4). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Flow Test Calculator sells 4 one-off in-app purchases. IAAI asks for nothing beyond the download.

IAAI holds the better App Store score, 5.0 against 4.1. That said, the two scores are not equally well evidenced: Flow Test Calculator has 63 ratings behind it against 4, so its average is the more settled of the two.

Flow Test Calculator ships an update every 90 months, IAAI every 5 months. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Flow Test Calculator | IAAI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.1 (63 ratings)](https://appshunter.io/ios/app/flow-test-calculator/id853530759/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/iaai/id1588771743/reviews)** |
| Number of ratings | **63** | 4 |
| Positive reviews | 68.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 90 months | **Every 5 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 2 MB | 47 MB |
| Requires iOS | **14.0** | 14.1 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Larry Owens](https://appshunter.io/developer/496138296) | [Results at Hand Software LLC](https://appshunter.io/developer/669416687) |

## What reviewers say

### Flow Test Calculator

[App page](https://appshunter.io/ios/app/flow-test-calculator/id853530759)

Calculate hydrant flow rates and determine maximum water system flow. This tool uses a standard variation of the Hazen-Williams formula for calculations. Imperial units are currently supported, with metric coming soon.

**Highlights:** Hydrant flow rate calculation, Maximum water system flow determination, Hazen-Williams formula implementation, Imperial unit support, Future metric unit support

**Features:** macOS Compatibility

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Disable Purchase Requests | $0.99 | one-time |
| Disable Purchase Requests 1.99 | $1.99 | one-time |
| Disable Purchase Request 4.99 | $4.99 | one-time |
| Disable Purchase Requests 9.99 | $9.99 | one-time |


### IAAI

[App page](https://appshunter.io/ios/app/iaai/id1588771743)

Access event details, agendas, and check-in information for fire investigation professionals. This app connects members of an international association dedicated to suppressing arson through professional investigation.

**Highlights:** Event information access, Agenda details, Evaluation forms, Check-in functionality, Maps

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Flow Test Calculator free?

Flow Test Calculator is free to download, with in-app purchases available.

### Is IAAI free?

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

### Which has better reviews, Flow Test Calculator or IAAI?

IAAI is rated higher. Flow Test Calculator averages 4.1 out of 5 from 63 ratings, while IAAI averages 5.0 from 4 ratings.

### Do Flow Test Calculator or IAAI have ads?

Neither Flow Test Calculator nor IAAI shows ads.

### Which is updated more often, Flow Test Calculator or IAAI?

Flow Test Calculator ships an update every 90 months, and IAAI every 5 months. Most recently, Flow Test Calculator was updated on October 23, 2026 and IAAI 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.*