# Prometheus Mobile STO vs YaArr

The clearest difference is in-app purchases: Prometheus Mobile STO at none against YaArr's 1. Prometheus Mobile STO also leads on iOS requirement (11.0 vs 26.0). YaArr's advantage is update cadence (fortnightly vs every 3 months). On price, ads and device support there is nothing between them.

Both are free to download. YaArr sells 1 one-off in-app purchase. Prometheus Mobile STO asks for nothing beyond the download.

Prometheus Mobile STO ships an update every 3 months, YaArr fortnightly. Both last shipped on September 14, 2026.

## The numbers

| Metric | Prometheus Mobile STO | YaArr |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (4 ratings)](https://appshunter.io/ios/app/yaarr/id6759206399/reviews)** |
| Number of ratings | — | **4** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Fortnightly** |
| Monetization | — | Free |
| Size | 41 MB | 32 MB |
| Requires iOS | **11.0** | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [PROMETHEUS GROUP, INC.](https://appshunter.io/developer/1554172551) | [GREG SCOTT MOORE](https://appshunter.io/developer/1865358451) |

## What reviewers say

### Prometheus Mobile STO

[App page](https://appshunter.io/ios/app/prometheus-mobile-sto/id6452803445)

**Features:** macOS Compatibility

**In-app purchases:** none


### YaArr

[App page](https://appshunter.io/ios/app/yaarr/id6759206399)

This app provides a unified remote interface for managing your self-hosted media server stack. It allows you to monitor and control various services like Sonarr, Radarr, and download clients directly from your iOS device. No cloud backend or account is required, ensuring your data stays private.

**Highlights:** Unified remote interface for media servers, Monitor Sonarr, Radarr, Lidarr, and more, Manage download clients and queues, Browse and manage media libraries, Discover and request media, Multi-server support and profiles, Secure credential storage

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| YaArr Pro - Remove Ads | $1.99 | one-time |


## Frequently asked questions

### Is Prometheus Mobile STO free?

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

### Is YaArr free?

YaArr is free to download, with in-app purchases available.

### Do Prometheus Mobile STO or YaArr have ads?

Neither Prometheus Mobile STO nor YaArr shows ads.

### Which is updated more often, Prometheus Mobile STO or YaArr?

Prometheus Mobile STO ships an update every 3 months, and YaArr fortnightly. Most recently, Prometheus Mobile STO was updated on September 14, 2026 and YaArr on September 14, 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.*