# Dri vs PRO

The clearest difference is rating: PRO at 4.9 against Dri's 3.6. PRO also leads on update cadence (every 2 weeks vs every 13 months) and ratings volume (110 vs 12). Dri's advantage is review sentiment (63% vs 30%) and device support (3 vs 1). 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.

PRO holds the better App Store score, 4.9 against 3.6. That said, the two scores are not equally well evidenced: PRO has 110 ratings behind it against 12, so its average is the more settled of the two. Written reviews complicate that: 63% of Dri's written reviews are positive against 30% of PRO's, so the app with the better star average is not the one people write more warmly about.

Dri ships an update every 13 months, PRO every 2 weeks. The most recent releases landed on October 9, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | Dri | PRO |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.6 (12 ratings)](https://appshunter.io/ios/app/dri-eaz-psychrometric-calc/id484266596/reviews) | **[4.9 (110 ratings)](https://appshunter.io/ios/app/pro-lab-247/id1251063238/reviews)** |
| Number of ratings | 12 | **110** |
| Positive reviews | **62.5% of reviews** | 30.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 13 months | **Every 2 weeks** |
| Monetization | Free | Free |
| Size | 4 MB | 9 MB |
| Requires iOS | **13.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Legend Brands](https://appshunter.io/developer/484266599) | [Professional Laboratories](https://appshunter.io/developer/1251063237) |

## What reviewers say

### Dri

[App page](https://appshunter.io/ios/app/dri-eaz-psychrometric-calc/id484266596)

This utility app calculates essential drying environment variables. Input temperature and relative humidity to instantly get grains per pound (GPP). Advanced options allow calculation of vapor pressure and air dew point to material, with easy term definitions.

**Highlights:** Calculate grains per pound (GPP), Calculate vapor pressure, Calculate air dew point to material, Switch between F° and C°, Easy-access term definitions

**Features:** macOS Compatibility

**In-app purchases:** none


### PRO

[App page](https://appshunter.io/ios/app/pro-lab-247/id1251063238)

Access comprehensive laboratory testing for environmental pollutants like mold, radon, and lead. This service is backed by certified professionals and offers simplified processing with bundled supplies and analysis fees.

**Highlights:** Mold testing, Radon testing, Lead testing, Allergen testing, Asbestos testing, Drinking water analysis, Certified professionals

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

**In-app purchases:** none


## Frequently asked questions

### Is Dri free?

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

### Is PRO free?

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

### Which has better reviews, Dri or PRO?

PRO is rated higher. Dri averages 3.6 out of 5 from 12 ratings, while PRO averages 4.9 from 110 ratings.

### Do Dri or PRO have ads?

Neither Dri nor PRO shows ads.

### Which is updated more often, Dri or PRO?

Dri ships an update every 13 months, and PRO every 2 weeks. Most recently, Dri was updated on October 9, 2026 and PRO on October 29, 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.*