# SolGlow vs FastWindow

The clearest difference is iOS requirement: FastWindow at 15.1 against SolGlow's 17.2. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. SolGlow sells 2 in-app purchases, starting at $9.99 per year and FastWindow sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | SolGlow | FastWindow |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.7 (3 ratings)](https://appshunter.io/ios/app/solglow-vitamin-d-tracker/id6763976252/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 10 days | — |
| Monetization | Freemium | — |
| Size | 10 MB | 37 MB |
| Requires iOS | 17.2 | **15.1** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPod |
| Age rating | 12+ | 4+ |
| Developer | [Michael Smith](https://appshunter.io/developer/1893971383) | [PROJECTSNAPLABS LTD](https://appshunter.io/developer/1889904681) |

## What reviewers say

### SolGlow

[App page](https://appshunter.io/ios/app/solglow-vitamin-d-tracker/id6763976252)

This app automatically estimates your daily vitamin D intake based on sunlight exposure, skin type, and location. It provides real-time UV index, burn-safe time remaining, and integrates with Apple Watch for effortless tracking. Features include winter mode, supplement check-ins, and advanced planning tools for Pro users.

**Highlights:** Automatic vitamin D estimation, Live UV index and IU-per-minute rate, Burn-safe time remaining with alerts, Winter Mode for low-sun periods, Supplement check-in, 7-day UV forecast (Pro), Trip Planner for jet lag (Pro)

**Features:** macOS Compatibility, Family Sharing, Apple Watch app, Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| SolGlow Pro Annual | $9.99 | per year |
| SolGlow Pro | $19.99 | one-time |


### FastWindow

[App page](https://appshunter.io/ios/app/fastwindow-fasting-timer/id6764386746)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| FastWindow Pro | $4.99 | one-time |


## Frequently asked questions

### Is SolGlow free?

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

### Is FastWindow free?

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

### Do SolGlow or FastWindow have ads?

Neither SolGlow nor FastWindow shows ads.

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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.*