# Im On Board vs Maritime Master

The clearest difference is in-app purchases: Im On Board at none against Maritime Master's 1. Im On Board also leads on iOS requirement (15.6 vs 17.6). Maritime Master's advantage is update cadence (daily vs every 9 days). On price, ads and device support there is nothing between them.

Both are free to download. Maritime Master sells 1 one-off in-app purchase. Im On Board asks for nothing beyond the download.

Im On Board ships an update every 9 days, Maritime Master daily. The most recent releases landed on October 25, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Im On Board | Maritime Master |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[3.0 (1 ratings)](https://appshunter.io/ios/app/maritime-master-calcdeck/id6760967809/reviews)** |
| Number of ratings | — | **1** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 9 days | **Daily** |
| Monetization | — | Free |
| Size | 25 MB | 7 MB |
| Requires iOS | **15.6** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 9+ |
| Developer | [Katarzyna Drop](https://appshunter.io/developer/1891804124) | [MARITIME MASTER LIMITED](https://appshunter.io/developer/1107589346) |

## What reviewers say

### Im On Board

[App page](https://appshunter.io/ios/app/im-on-board/id6738877462)

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

**In-app purchases:** none


### Maritime Master

[App page](https://appshunter.io/ios/app/maritime-master-calcdeck/id6760967809)

This app provides a comprehensive suite of 88 professional maritime calculators for navigation, celestial observation, tides, stability, weather, engineering, and more. It's designed for maritime professionals and enthusiasts, offering offline functionality and citing all formulas with their official sources.

**Highlights:** 88 professional maritime calculators, Offline functionality, Navigation calculations, Celestial observation tools, Stability and cargo calculations, Unit converters

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| CalcDeck Pro | $14.99 | one-time |


## Frequently asked questions

### Is Im On Board free?

Im On Board is free to download, with no in-app purchases.

### Is Maritime Master free?

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

### Do Im On Board or Maritime Master have ads?

Neither Im On Board nor Maritime Master shows ads.

### Which is updated more often, Im On Board or Maritime Master?

Im On Board ships an update every 9 days, and Maritime Master daily. Most recently, Im On Board was updated on October 25, 2026 and Maritime Master on October 31, 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.*