# METRA Building Doc vs WindowViewer

The clearest difference is update cadence: METRA Building Doc at every 3 weeks against WindowViewer's every 3 months. 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.

METRA Building Doc ships an update every 3 weeks, WindowViewer every 3 months. The most recent releases landed on October 1, 2026 and September 10, 2026 respectively.

## The numbers

| Metric | METRA Building Doc | WindowViewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 3 months |
| Size | 14 MB | 138 MB |
| Requires iOS | 13.6 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [METRA - METALLURGICA TRAFILATI ALLUMINIO S.P.A.](https://appshunter.io/developer/438414105) | [Digital Building Solutions GmbH](https://appshunter.io/developer/1456095004) |

## What reviewers say

### METRA Building Doc

[App page](https://appshunter.io/ios/app/metra-building-doc/id1577779281)

**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 METRA Building Doc free?

METRA Building Doc is free to download, with no in-app purchases.

### Is WindowViewer free?

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

### Do METRA Building Doc or WindowViewer have ads?

Neither METRA Building Doc nor WindowViewer shows ads.

### Which is updated more often, METRA Building Doc or WindowViewer?

METRA Building Doc ships an update every 3 weeks, and WindowViewer every 3 months. Most recently, METRA Building Doc was updated on October 1, 2026 and WindowViewer on September 10, 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.*