# Silent Observer vs Mobile SOS

The clearest difference is iOS requirement: Silent Observer at 9.0 against Mobile SOS's 13.0. 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.

Silent Observer ships an update every 34 months, Mobile SOS every 44 months. The most recent releases landed on October 4, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Silent Observer | Mobile SOS |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 34 months** | Every 44 months |
| Size | 30 MB | 36 MB |
| Requires iOS | **9.0** | 13.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Navigate360, LLC](https://appshunter.io/developer/1562199710) | [SOS, Inc.](https://appshunter.io/developer/1658400757) |

## What reviewers say

### Silent Observer

[App page](https://appshunter.io/ios/app/silent-observer/id1209909707)

**Features:** macOS Compatibility

**In-app purchases:** none


### Mobile SOS

[App page](https://appshunter.io/ios/app/mobile-sos/id1658400755)

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

**In-app purchases:** none


## Frequently asked questions

### Is Silent Observer free?

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

### Is Mobile SOS free?

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

### Do Silent Observer or Mobile SOS have ads?

Neither Silent Observer nor Mobile SOS shows ads.

### Which is updated more often, Silent Observer or Mobile SOS?

Silent Observer ships an update every 34 months, and Mobile SOS every 44 months. Most recently, Silent Observer was updated on October 4, 2026 and Mobile SOS on October 13, 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.*