# Prolon Focus vs DuctCalc.Ca

The clearest difference is rating: Prolon Focus at 4.5 against DuctCalc.Ca's 1.9. Prolon Focus also leads on in-app purchases (none vs 4) and update cadence (fortnightly vs every 4 months). DuctCalc.Ca's advantage is iOS requirement (11.3 vs 17.0). On price, ads and device support there is nothing between them.

Both are free to download. DuctCalc.Ca sells 4 one-off in-app purchases. Prolon Focus asks for nothing beyond the download.

Prolon Focus holds the better App Store score, 4.5 against 1.9. Both are backed by a comparable volume of ratings — 89 and 20 respectively. Written reviews point the same way: 75% of Prolon Focus's written reviews are positive against 50% of DuctCalc.Ca's.

Prolon Focus ships an update fortnightly, DuctCalc.Ca every 4 months. The most recent releases landed on October 24, 2026 and October 17, 2026 respectively.

## The numbers

| Metric | Prolon Focus | DuctCalc.Ca |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (89 ratings)](https://appshunter.io/ios/app/prolon-focus/id1050748696/reviews)** | [1.9 (20 ratings)](https://appshunter.io/ios/app/ductcalcca/id1434460375/reviews) |
| Number of ratings | **89** | 20 |
| Positive reviews | **75.0% of reviews** | 50.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 4 months |
| Monetization | **Ad-supported** | Free with in-app purchases |
| Size | 51 MB | 9 MB |
| Requires iOS | 17.0 | **11.3** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Prolon Inc](https://appshunter.io/developer/1050748695) | [Firas Kneifati](https://appshunter.io/developer/1434460374) |

## What reviewers say

### Prolon Focus

[App page](https://appshunter.io/ios/app/prolon-focus/id1050748696)

This app offers a graphical interface for visualizing and configuring Prolon zoning systems. It supports cloud storage for projects, allowing sharing and note attachment. Snapshots can also be created and transferred between users.

**Highlights:** Visualize Prolon zoning systems, Configure Prolon zoning systems, Graphical user interface, Cloud storage for projects, Share projects with users, Attach project notes, Create and copy snapshots

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

**In-app purchases:** none


### DuctCalc.Ca

[App page](https://appshunter.io/ios/app/ductcalcca/id1434460375)

This utility app calculates duct dimensions and air velocity using two methods: Equal Friction and Velocity. It supports both round and rectangular ducts, offering precise calculations for HVAC professionals. Offline functionality is available with a subscription.

**Highlights:** Duct sizing calculator, Equal Friction Method, Velocity Method, Round and rectangular duct support, Offline functionality, Full air flow range activation

**Features:** macOS Compatibility

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| One Month Full Air Flow | $6.99 | one-time |
| Three Months Full Air Flow | $17.99 | one-time |
| Six Months Full Air Flow | $29.99 | one-time |
| One Year Full Air Flow | $49.99 | one-time |


## Frequently asked questions

### Is Prolon Focus free?

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

### Is DuctCalc.Ca free?

DuctCalc.Ca is free to download, with in-app purchases available.

### Which has better reviews, Prolon Focus or DuctCalc.Ca?

Prolon Focus is rated higher. Prolon Focus averages 4.5 out of 5 from 89 ratings, while DuctCalc.Ca averages 1.9 from 20 ratings.

### Do Prolon Focus or DuctCalc.Ca have ads?

Neither Prolon Focus nor DuctCalc.Ca shows ads.

### Which is updated more often, Prolon Focus or DuctCalc.Ca?

Prolon Focus ships an update fortnightly, and DuctCalc.Ca every 4 months. Most recently, Prolon Focus was updated on October 24, 2026 and DuctCalc.Ca on October 17, 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.*