# IEQ Calculator (Classroom) vs PolyU Library

The clearest difference is update cadence: IEQ Calculator (Classroom) at every 6 days against PolyU Library's every 3 months. IEQ Calculator (Classroom) also leads on iOS requirement (13.0 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.

IEQ Calculator (Classroom) ships an update every 6 days, PolyU Library every 3 months. The most recent releases landed on September 28, 2026 and October 14, 2026 respectively.

## The numbers

| Metric | IEQ Calculator (Classroom) | PolyU Library |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 days** | Every 3 months |
| Size | 1 MB | 35 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Fishball Studio](https://appshunter.io/developer/418104683) | [The Hong Kong Polytechnic University](https://appshunter.io/developer/442903588) |

## What reviewers say

### IEQ Calculator (Classroom)

[App page](https://appshunter.io/ios/app/ieq-calculator-classroom/id870377033)

**Features:** macOS Compatibility

**In-app purchases:** none


### PolyU Library

[App page](https://appshunter.io/ios/app/polyu-library/id6450161237)

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

**In-app purchases:** none


## Frequently asked questions

### Is IEQ Calculator (Classroom) free?

IEQ Calculator (Classroom) is free to download, with no in-app purchases.

### Is PolyU Library free?

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

### Do IEQ Calculator (Classroom) or PolyU Library have ads?

Neither IEQ Calculator (Classroom) nor PolyU Library shows ads.

### Which is updated more often, IEQ Calculator (Classroom) or PolyU Library?

IEQ Calculator (Classroom) ships an update every 6 days, and PolyU Library every 3 months. Most recently, IEQ Calculator (Classroom) was updated on September 28, 2026 and PolyU Library on October 14, 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.*