# OSS Messenger vs KLARO App

The clearest difference is review sentiment: KLARO App at 100% against OSS Messenger's 67%. KLARO App also leads on update cadence (weekly vs every 5 weeks). 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.

OSS Messenger ships an update every 5 weeks, KLARO App weekly. The most recent releases landed on October 8, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | OSS Messenger | KLARO App |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 66.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 5 weeks | **Weekly** |
| Monetization | Free | Free |
| Size | 52 MB | 190 MB |
| Requires iOS | 15.0 | **14.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Sdui GmbH](https://appshunter.io/developer/1034926222) | [Verein Programm Klasse2000 e.V.](https://appshunter.io/developer/1707335300) |

## What reviewers say

### OSS Messenger

[App page](https://appshunter.io/ios/app/oss-messenger/id1618783644)

This app facilitates secure and mobile communication for teachers, students, and parents within the Saarland education system. It enables direct messages, group chats, voice messages, video conferences, and translation features to enhance school-wide communication.

**Highlights:** Secure messaging, Group and voice messages, Video conferences, Translation feature, Surveys and polls, Read receipts, Customizable availability times

**Features:** Vision Pro support

**In-app purchases:** none


### KLARO App

[App page](https://appshunter.io/ios/app/klaro-app/id6466402729)

This app offers engaging movement breaks and relaxation exercises inspired by a popular school health program. It provides 63 guided activities, including breathing techniques and story-based relaxation, to promote well-being for children and families. The content is accessible offline and includes resources for parents.

**Highlights:** Guided movement breaks, Relaxation exercises, Breathing techniques, Story-based relaxation, Offline access, Parental resources

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is OSS Messenger free?

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

### Is KLARO App free?

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

### Do OSS Messenger or KLARO App have ads?

Neither OSS Messenger nor KLARO App shows ads.

### Which is updated more often, OSS Messenger or KLARO App?

OSS Messenger ships an update every 5 weeks, and KLARO App weekly. Most recently, OSS Messenger was updated on October 8, 2026 and KLARO App on October 20, 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.*