# Pilkington Spectrum vs WindowViewer

The clearest difference is ads: WindowViewer at none against Pilkington Spectrum's shown. Pilkington Spectrum's advantage is iOS requirement (9.3 vs 12.0). On price, update cadence, 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.

Both ship on a similar rhythm, roughly every 3 months. The most recent releases landed on October 14, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Pilkington Spectrum | WindowViewer |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | Yes | **No** |
| Update frequency | Every 3 months | Every 3 months |
| Monetization | Ad-supported | — |
| Size | 87 MB | 138 MB |
| Requires iOS | **9.3** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Pilkington Group Ltd](https://appshunter.io/developer/1184941969) | [Digital Building Solutions GmbH](https://appshunter.io/developer/1456095004) |

## What reviewers say

### Pilkington Spectrum

[App page](https://appshunter.io/ios/app/pilkington-spectrum/id1184941970)

This application calculates key properties of insulating glass units, including light, solar, and sound insulation values. It provides detailed information on various glazing configurations and product ranges. Access technical contacts for further assistance.

**Highlights:** Calculate light and solar properties, Determine centre pane U-value, Assess sound insulation values, Analyze UV transmittance and color rendering, Evaluate impact resistance and fire resistance, Access comprehensive product database, Find technical contact information

**Features:** macOS Compatibility

**In-app purchases:** none


### WindowViewer

[App page](https://appshunter.io/ios/app/windowviewer/id1606181528)

**In-app purchases:** none


## Frequently asked questions

### Is Pilkington Spectrum free?

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

### Is WindowViewer free?

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

### Do Pilkington Spectrum or WindowViewer have ads?

Pilkington Spectrum shows ads; WindowViewer does not.

### Which is updated more often, Pilkington Spectrum or WindowViewer?

Pilkington Spectrum ships an update every 3 months, and WindowViewer every 3 months. Most recently, Pilkington Spectrum was updated on October 14, 2026 and WindowViewer on October 12, 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.*