# COMP Odour Survey vs Smell Annotator

The clearest difference is update cadence: Smell Annotator at monthly against COMP Odour Survey's every 6 months. On price, ads, in-app purchases and monetization model there is nothing between them.

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

COMP Odour Survey ships an update every 6 months, Smell Annotator monthly. The most recent releases landed on October 22, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | COMP Odour Survey | Smell Annotator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[1.0 (1 ratings)](https://appshunter.io/ios/app/smell-annotator/id1607528175/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 6 months | **Monthly** |
| Monetization | Free | Free |
| Size | 45 MB | 53 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Wood Buffalo Environmental Association](https://appshunter.io/developer/1281094252) | [SmartNanotubes Technologies](https://appshunter.io/developer/1607528177) |

## What reviewers say

### COMP Odour Survey

[App page](https://appshunter.io/ios/app/comp-odour-survey/id1281094253)

This app allows the public to report odour events in the Wood Buffalo region. The collected anonymous data helps researchers understand the relationship between odours and ambient air quality, complementing official monitoring station data.

**Highlights:** Anonymous odour reporting, Contributes to air quality research, Data complements monitoring stations, Supports Wood Buffalo Environmental Association, Community participation in environmental monitoring

**Features:** macOS Compatibility

**In-app purchases:** none


### Smell Annotator

[App page](https://appshunter.io/ios/app/smell-annotator/id1607528175)

This application enables machines to digitally sense and analyze smells using nanomaterial-based technology. It allows users to view, annotate, and recognize smell measurements in real-time, functioning as part of a developer kit.

**Highlights:** Smell recognition, Smell digitalization and annotation, Saving and loading measurements, Real-time measurement visualization, Offline data collection, Graph synchronization

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is COMP Odour Survey free?

COMP Odour Survey is free to download, with no in-app purchases.

### Is Smell Annotator free?

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

### Do COMP Odour Survey or Smell Annotator have ads?

Neither COMP Odour Survey nor Smell Annotator shows ads.

### Which is updated more often, COMP Odour Survey or Smell Annotator?

COMP Odour Survey ships an update every 6 months, and Smell Annotator monthly. Most recently, COMP Odour Survey was updated on October 22, 2026 and Smell Annotator 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.*