# AVL CalApp vs Duct Sensor Assistant

The clearest difference is iOS requirement: AVL CalApp at 7.0 against Duct Sensor Assistant's 12.0. On price, update cadence, ads and in-app purchases there is nothing between them.

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

AVL CalApp ships an update every 7 months, Duct Sensor Assistant every 6 months. The most recent releases landed on September 28, 2026 and October 6, 2026 respectively.

## The numbers

| Metric | AVL CalApp | Duct Sensor Assistant |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 6 months** |
| Size | 8 MB | 31 MB |
| Requires iOS | **7.0** | 12.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [AVL List GmbH](https://appshunter.io/developer/1225134805) | [BELIMO Automation AG](https://appshunter.io/developer/1149281298) |

## What reviewers say

### AVL CalApp

[App page](https://appshunter.io/ios/app/avl-calapp/id1225231296)

**Features:** macOS Compatibility

**In-app purchases:** none


### Duct Sensor Assistant

[App page](https://appshunter.io/ios/app/duct-sensor-assistant/id1559862597)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is AVL CalApp free?

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

### Is Duct Sensor Assistant free?

Duct Sensor Assistant is free to download, with no in-app purchases.

### Do AVL CalApp or Duct Sensor Assistant have ads?

Neither AVL CalApp nor Duct Sensor Assistant shows ads.

### Which is updated more often, AVL CalApp or Duct Sensor Assistant?

AVL CalApp ships an update every 7 months, and Duct Sensor Assistant every 6 months. Most recently, AVL CalApp was updated on September 28, 2026 and Duct Sensor Assistant on October 6, 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.*