# "proOSBB" vs Навигационная линейка

The clearest difference is in-app purchases: "proOSBB" at none against Навигационная линейка's 1. "proOSBB" also leads on update cadence (every 2 months vs every 5 months). Навигационная линейка's advantage is iOS requirement (11.0 vs 15.1). On price, ads and device support there is nothing between them.

Both are free to download. Навигационная линейка sells 1 one-off in-app purchase. "proOSBB" asks for nothing beyond the download.

"proOSBB" ships an update every 2 months, Навигационная линейка every 5 months. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | "proOSBB" | Навигационная линейка |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/id1528938414/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 78.6% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 5 months |
| Monetization | — | Free with in-app purchases |
| Size | 54 MB | 30 MB |
| Requires iOS | 15.1 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [TSENTR MUNITSYPALNYKH SYSTEM UPRAVLINNIA, TOV](https://appshunter.io/developer/1321819688) | [Grigorii Ovinkin](https://appshunter.io/developer/1448812067) |

## What reviewers say

### "proOSBB"

[App page](https://appshunter.io/ios/app/proosbb/id1385502270)

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

**In-app purchases:** none


### Навигационная линейка

[App page](https://appshunter.io/ios/app/id1528938414)

This app is a digital replica of the Soviet NL-10m navigation slide rule. It's designed for flight and navigation calculations using logarithmic principles. Beyond the slide rule, it offers tools for solving specific navigation problems.

**Highlights:** Digital NL-10m slide rule, Logarithmic scale calculations, Flight and navigation tasks, Specific navigation problem solver

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Отключение рекламы | $1.99 | one-time |


## Frequently asked questions

### Is "proOSBB" free?

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

### Is Навигационная линейка free?

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

### Do "proOSBB" or Навигационная линейка have ads?

Neither "proOSBB" nor Навигационная линейка shows ads.

### Which is updated more often, "proOSBB" or Навигационная линейка?

"proOSBB" ships an update every 2 months, and Навигационная линейка every 5 months. Most recently, "proOSBB" was updated on October 26, 2026 and Навигационная линейка on October 24, 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.*