# O vs ENGEL e

The clearest difference is update cadence: O at every 6 weeks against ENGEL e's every 7 months. O also leads on iOS requirement (12.0 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.

O ships an update every 6 weeks, ENGEL e every 7 months. The most recent releases landed on October 12, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | O | ENGEL e |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 7 months |
| Size | 40 MB | 19 MB |
| Requires iOS | **12.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [HUTCHINSON](https://appshunter.io/developer/862345826) | [ENGEL AUSTRIA GmbH](https://appshunter.io/developer/687631542) |

## What reviewers say

### O

[App page](https://appshunter.io/ios/app/o-ring/id1229032846)

**Features:** macOS Compatibility

**In-app purchases:** none


### ENGEL e

[App page](https://appshunter.io/ios/app/engel-e-vent/id6449192345)

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

**In-app purchases:** none


## Frequently asked questions

### Is O free?

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

### Is ENGEL e free?

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

### Do O or ENGEL e have ads?

Neither O nor ENGEL e shows ads.

### Which is updated more often, O or ENGEL e?

O ships an update every 6 weeks, and ENGEL e every 7 months. Most recently, O was updated on October 12, 2026 and ENGEL e on October 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.*