# Windmill Propane vs DAWN Inspector

The clearest difference is update cadence: DAWN Inspector at every 2 months against Windmill Propane's every 23 months. Windmill Propane's advantage is iOS requirement (12.2 vs 15.0). On price, ads, in-app purchases and device support there is nothing between them.

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

Windmill Propane ships an update every 23 months, DAWN Inspector every 2 months. Both last shipped on November 3, 2026.

## The numbers

| Metric | Windmill Propane | DAWN Inspector |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.0 (2 ratings)](https://appshunter.io/ios/app/dawn-inspector-carb-approved/id6449002686/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 50.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 23 months | **Every 2 months** |
| Monetization | — | Free |
| Size | 46 MB | 2 MB |
| Requires iOS | **12.2** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [EDPO, LLC](https://appshunter.io/developer/1521548149) | [HEM Data Corporation](https://appshunter.io/developer/1654791950) |

## What reviewers say

### Windmill Propane

[App page](https://appshunter.io/ios/app/windmill-propane/id1583996012)

**Features:** macOS Compatibility

**In-app purchases:** none


### DAWN Inspector

[App page](https://appshunter.io/ios/app/dawn-inspector-carb-approved/id6449002686)

This app connects to your vehicle's network to perform emissions tests. It guides you through a quick, two-minute process to ensure your car meets CARB standards.

**Highlights:** CARB-approved emissions testing, Vehicle network connection, Quick 2-minute test completion, Engine on test initiation, Hardware attachment required

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

**In-app purchases:** none


## Frequently asked questions

### Is Windmill Propane free?

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

### Is DAWN Inspector free?

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

### Do Windmill Propane or DAWN Inspector have ads?

Neither Windmill Propane nor DAWN Inspector shows ads.

### Which is updated more often, Windmill Propane or DAWN Inspector?

Windmill Propane ships an update every 23 months, and DAWN Inspector every 2 months. Most recently, Windmill Propane was updated on November 3, 2026 and DAWN Inspector on November 3, 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.*