# Vitamin D Window Widget vs RayDay

The clearest difference is rating: Vitamin D Window Widget at 5.0 against RayDay's 3.0. Vitamin D Window Widget also leads on in-app purchases (none vs 3). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. RayDay sells 3 in-app purchases, starting at $4.99 per 7 days. Vitamin D Window Widget asks for nothing beyond the download.

Vitamin D Window Widget holds the better App Store score, 5.0 against 3.0. Both are backed by a comparable volume of ratings — 2 and 2 respectively.

Vitamin D Window Widget ships an update every 2 weeks, RayDay every 3 weeks. Both last shipped on October 31, 2026.

## The numbers

| Metric | Vitamin D Window Widget | RayDay |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/vitamin-d-window-widget/id6759223422/reviews)** | [3.0 (2 ratings)](https://appshunter.io/ios/app/rayday-vitamin-d-tracker/id6761286896/reviews) |
| Number of ratings | 2 | 2 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Every 2 weeks** | Every 3 weeks |
| Monetization | **Free** | Freemium |
| Size | 2 MB | 26 MB |
| Requires iOS | 18.0 | **17.0** |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 4+ |
| Developer | [Airhopping, SL](https://appshunter.io/developer/1339572434) | [Jakub Laszczyk](https://appshunter.io/developer/568719342) |

## What reviewers say

### Vitamin D Window Widget

[App page](https://appshunter.io/ios/app/vitamin-d-window-widget/id6759223422)

This app displays the optimal times of day for natural vitamin D production based on your location and the sun's elevation. It offers real-time sun schedules, smart widgets for home screen access, and notifications to help you maximize your sun exposure.

**Highlights:** Real-time sun schedule, Smart widgets, Daily schedule updates, Dynamic Island countdown, Location-based calculations, Offline functionality, Solar-themed design

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

**In-app purchases:** none


### RayDay

[App page](https://appshunter.io/ios/app/rayday-vitamin-d-tracker/id6761286896)

This app helps you understand your daily window for natural Vitamin D production. It calculates optimal sun exposure times based on your location and skin type, providing forecasts and real-time atmospheric data.

**Highlights:** D-Window Calculator, Live Solar Path animation, 7-Day D-Window Forecast, Skin Type Personalization, Smart Notifications, Real-time Atmospheric Data, Home Screen Widget

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| RayDay Weekly | $4.99 | per 7 days |
| RayDay Yearly | $24.99 | per year |
| Early Supporter Yearly | $24.99 | per year |


## Frequently asked questions

### Is Vitamin D Window Widget free?

Vitamin D Window Widget is free to download, with no in-app purchases.

### Is RayDay free?

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

### Which has better reviews, Vitamin D Window Widget or RayDay?

Vitamin D Window Widget is rated higher. Vitamin D Window Widget averages 5.0 out of 5 from 2 ratings, while RayDay averages 3.0 from 2 ratings.

### Do Vitamin D Window Widget or RayDay have ads?

Neither Vitamin D Window Widget nor RayDay shows ads.

### Which is updated more often, Vitamin D Window Widget or RayDay?

Vitamin D Window Widget ships an update every 2 weeks, and RayDay every 3 weeks. Most recently, Vitamin D Window Widget was updated on October 31, 2026 and RayDay 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.*