# Windmill Air vs Engine Displacement Calc

The clearest difference is price: Windmill Air at Free against Engine Displacement Calc's $4.99. On update cadence, ads, in-app purchases and device support there is nothing between them.

Windmill Air is free to download; Engine Displacement Calc costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Windmill Air ships an update every 2 months, Engine Displacement Calc every 6 weeks. The most recent releases landed on October 22, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Windmill Air | Engine Displacement Calc |
| --- | --- | --- |
| Price | **Free** | $4.99 |
| Rating | **[4.7 (6.2K ratings)](https://appshunter.io/ios/app/windmill-air/id1589463108/reviews)** | — |
| Number of ratings | **6.2K** | — |
| Positive reviews | 27.9% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 6 weeks** |
| Monetization | Free | — |
| Size | 83 MB | 1 MB |
| Requires iOS | **16.4** | 17.0 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [The Air Lab, Inc.](https://appshunter.io/developer/1521133311) | [Shanghai Sheyuan Network Technology Co., Ltd.](https://appshunter.io/developer/1560626858) |

## What reviewers say

### Windmill Air

[App page](https://appshunter.io/ios/app/windmill-air/id1589463108)

This app allows you to remotely control your smart air care devices. Set schedules and adjust settings to create your ideal home climate from anywhere.

**Highlights:** Remote product control, Set automation schedules, Adjust any setting, Create ideal home climate, Eco-friendly product integration

**In-app purchases:** none

**What reviewers like**

- 🚀 Aesthetically pleasing design
- 🚀 Quiet operation
- 🚀 Easy installation
- 👍 Responsive app
- 👍 Useful remote control features

**What reviewers complain about**

- 🐛 Inaccurate temperature readings
- 🐛 Unreliable app connectivity and functionality
- 🐛 Automation issues and failures
- 🐛 Inconsistent settings and mode changes
- 🐛 Glitchy app with frequent bugs

**Reported bugs**

- App unable to maintain accurate room temperature readings
- Automations not working as expected or reverting settings
- Connectivity issues causing the app to lose control of the unit
- Inconsistent behavior when turning the unit on/off or changing settings

**Requested features**

- Integration with smart home platforms
- Improved automation and scheduling capabilities
- More granular temperature and fan speed controls
- Ability to disable annoying app notifications


### Engine Displacement Calc

[App page](https://appshunter.io/ios/app/engine-displacement-calc/id6761711493)

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

**In-app purchases:** none


## Frequently asked questions

### Is Windmill Air free?

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

### Is Engine Displacement Calc free?

Engine Displacement Calc costs $4.99, with no in-app purchases.

### Do Windmill Air or Engine Displacement Calc have ads?

Neither Windmill Air nor Engine Displacement Calc shows ads.

### Which is updated more often, Windmill Air or Engine Displacement Calc?

Windmill Air ships an update every 2 months, and Engine Displacement Calc every 6 weeks. Most recently, Windmill Air was updated on October 22, 2026 and Engine Displacement Calc on October 18, 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.*