# app4sail vs Nautical Calculator Preview

The clearest difference is price: Nautical Calculator Preview at Free against app4sail's $4.99. Nautical Calculator Preview also leads on update cadence (every 2 weeks vs every 3 months). app4sail's advantage is ads (none vs shown) and iOS requirement (15.6 vs 17.0). On in-app purchases and device support there is nothing between them.

Nautical Calculator Preview is free to download; app4sail costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

app4sail ships an update every 3 months, Nautical Calculator Preview every 2 weeks. The most recent releases landed on October 21, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | app4sail | Nautical Calculator Preview |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/nautical-calculator-preview/id1534074231/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | No | No |
| Ads | **No** | Yes |
| Update frequency | Every 3 months | **Every 2 weeks** |
| Monetization | — | Ad-supported |
| Size | 8 MB | 33 MB |
| Requires iOS | **15.6** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [anton van oosten](https://appshunter.io/developer/641322651) | [The Vu Cong](https://appshunter.io/developer/1532372627) |

## What reviewers say

### app4sail

[App page](https://appshunter.io/ios/app/app4sail/id641578574)

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

**In-app purchases:** none


### Nautical Calculator Preview

[App page](https://appshunter.io/ios/app/nautical-calculator-preview/id1534074231)

This app provides comprehensive tools for marine navigation, including real-time ship movement, route planning, and advanced sailing calculations. It also offers features for collision avoidance, maneuvering, and learning maritime regulations and signaling.

**Highlights:** Real-time ship movement, Route planning, Mercator and Great Circle sailing, Collision avoidance, Maneuvering calculations, COLREGs and maritime signaling, Offline GPS

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

**In-app purchases:** none


## Frequently asked questions

### Is app4sail free?

app4sail costs $4.99, with no in-app purchases.

### Is Nautical Calculator Preview free?

Nautical Calculator Preview is free to download, with no in-app purchases.

### Do app4sail or Nautical Calculator Preview have ads?

Nautical Calculator Preview shows ads; app4sail does not.

### Which is updated more often, app4sail or Nautical Calculator Preview?

app4sail ships an update every 3 months, and Nautical Calculator Preview every 2 weeks. Most recently, app4sail was updated on October 21, 2026 and Nautical Calculator Preview on October 7, 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.*