# Sun Calendar vs Avalon Offshore

The clearest difference is price: Sun Calendar at $2.99 against Avalon Offshore's $35.00. Sun Calendar also leads on in-app purchases (none vs 21) and chart position (#102 vs unranked). Avalon Offshore's advantage is update cadence (every 3 weeks vs every 5 months) and review sentiment (75% vs 63%). On ads and device support there is nothing between them.

Sun Calendar costs $2.99 and Avalon Offshore $35.00 up front. Avalon Offshore sells 21 in-app purchases, starting at $39.99 per year. Sun Calendar asks for nothing beyond the download.

Sun Calendar ships an update every 5 months, Avalon Offshore every 3 weeks. The most recent releases landed on October 18, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Sun Calendar | Avalon Offshore |
| --- | --- | --- |
| Price | **$2.99** | $35.00 |
| Rating | **[4.3 (43 ratings)](https://appshunter.io/ios/app/sun-calendar/id748920235/reviews)** | — |
| Number of ratings | **43** | — |
| Positive reviews | 63.0% of reviews | **75.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | **Every 3 weeks** |
| Monetization | **Free** | Free with in-app purchases |
| Best chart rank | **#102** | — |
| Size | 15 MB | 66 MB |
| Requires iOS | **8.1** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Steven Edwards](https://appshunter.io/developer/748920238) | [Avalon Navigation Systems](https://appshunter.io/developer/1802181177) |

## What reviewers say

### Sun Calendar

[App page](https://appshunter.io/ios/app/sun-calendar/id748920235)

**Currently charting:** #102 Top Paid · Weather (US App Store)

Access detailed sunrise, sunset, and moon phase information with customizable calendars. Generate and share PDF or CSV reports, and track the sun's movement throughout the day. Offers thousands of predefined locations worldwide.

**Highlights:** Daily sunrise and sunset times, Moonrise, moonset, and moon phase data, Customizable multi-month calendars, Printable PDF and CSV reports, Location tracking and favorites, Map with distance measurement

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

**In-app purchases:** none


### Avalon Offshore

[App page](https://appshunter.io/ios/app/avalon-offshore/id975313021)

This app provides advanced weather routing and navigation for sailors. It offers detailed weather forecasts from numerous models, collision alerts, and route optimization based on boat draft. Compatible with various nautical maps and augmented reality glasses.

**Highlights:** Advanced weather routing, NMEA 0183 and AIS integration, Collision alarm, Regatta start management, 65 automatic weather models, Bathymetric routing, Navionics Boating map compatibility

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

**In-app purchases (21)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Subscription | $39.99 | per year |
| England and Ireland South 2024 | $29.00 | one-time |
| Portugal and Spain North 2024 | $29.00 | one-time |
| East Mediterranean 2024 | $29.00 | one-time |
| Transatlantic Islands 2024 | $29.00 | one-time |
| West Mediterranean 2024 | $29.00 | one-time |
| Benelux and England East 2024 | $29.00 | one-time |
| East Mediterranean 2023 | $39.00 | one-time |
| Benelux and England East 2022 | $39.00 | one-time |
| England and Ireland South 2023 | $39.00 | one-time |
| Transatlantic Islands 2023 | $39.00 | one-time |
| West Mediterranean 2023 | $39.00 | one-time |
| Portugal and Spain North 2023 | $39.00 | one-time |
| UK and Ireland 2024 | $39.00 | one-time |
| UK and Ireland 2023 | $49.00 | one-time |
| France Mediterranee 2023 SHOM | $99.99 | one-time |
| Lesser Antillas 2023 | $99.99 | one-time |
| SHOM 2024 - France Med | $99.99 | one-time |
| Lesser Antillas 2024 | $99.99 | one-time |
| SHOM 2024 - France Manche | $99.99 | one-time |
| SHOM 2024 - France Atlantique | $99.99 | one-time |


## Frequently asked questions

### Is Sun Calendar free?

Sun Calendar costs $2.99, with no in-app purchases.

### Is Avalon Offshore free?

Avalon Offshore costs $35.00, and also offers in-app purchases.

### Do Sun Calendar or Avalon Offshore have ads?

Neither Sun Calendar nor Avalon Offshore shows ads.

### Which is updated more often, Sun Calendar or Avalon Offshore?

Sun Calendar ships an update every 5 months, and Avalon Offshore every 3 weeks. Most recently, Sun Calendar was updated on October 18, 2026 and Avalon Offshore on October 8, 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.*