# Rays vs The Belly Button

The clearest difference is rating: The Belly Button at 5.0 against Rays's 4.4. The Belly Button also leads on review sentiment (100% vs 75%) and update cadence (every 2 days vs weekly). On price, ratings volume, ads and in-app purchases there is nothing between them.

Both are free to download. Rays sells 2 in-app purchases, starting at $4.99 per month and The Belly Button sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

The Belly Button holds the better App Store score, 5.0 against 4.4. Both are backed by a comparable volume of ratings — 7 and 6 respectively. Written reviews point the same way: 75% of Rays's written reviews are positive against 100% of The Belly Button's.

Rays ships an update weekly, The Belly Button every 2 days. The most recent releases landed on November 8, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | Rays | The Belly Button |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.4 (7 ratings)](https://appshunter.io/ios/app/rays-auto-vitamin-d-tracking/id6752499967/reviews) | **[5.0 (6 ratings)](https://appshunter.io/ios/app/the-belly-button/id6766549502/reviews)** |
| Number of ratings | **7** | 6 |
| Positive reviews | 75.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Weekly | **Every 2 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 58 MB | 54 MB |
| Requires iOS | 15.1 | 15.1 |
| Devices | iPhone, iPod | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Rays Health Technologies LLC](https://appshunter.io/developer/1829292925) | [Chemmo Holdings, LLC](https://appshunter.io/developer/1895944832) |

## What reviewers say

### Rays

[App page](https://appshunter.io/ios/app/rays-auto-vitamin-d-tracking/id6752499967)

Automatically tracks your body's vitamin D synthesis from sun exposure. Get personalized recommendations for optimal timing and duration to maintain energy, mood, and skin health year-round without manual logging.

**Highlights:** Automatic vitamin D synthesis tracking, Personalized health intelligence, Smart sun exposure recommendations, Progress tracking and health insights, Apple Health integration, Minimal battery usage

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Rays - Auto Vitamin D Tracker | $4.99 | per month |
| Rays - Auto Vitamin D Tracker | $19.99 | per year |


### The Belly Button

[App page](https://appshunter.io/ios/app/the-belly-button/id6766549502)

This app simplifies labor alerts by allowing expectant mothers to instantly notify their care team, family, and friends with a single tap. It allows for customizable notification groups and delivery methods, ensuring timely communication during labor and beyond.

**Highlights:** One-tap labor alerts, Customizable notification groups, Multiple contact methods (push, SMS, email), Milestone broadcasts, Newborn photo sharing, Distinct alert sound for urgent notifications

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 12 Months of Access | $9.99 | one-time |


## Frequently asked questions

### Is Rays free?

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

### Is The Belly Button free?

The Belly Button is free to download, with in-app purchases available.

### Which has better reviews, Rays or The Belly Button?

The Belly Button is rated higher. Rays averages 4.4 out of 5 from 7 ratings, while The Belly Button averages 5.0 from 6 ratings.

### Do Rays or The Belly Button have ads?

Neither Rays nor The Belly Button shows ads.

### Which is updated more often, Rays or The Belly Button?

Rays ships an update weekly, and The Belly Button every 2 days. Most recently, Rays was updated on November 8, 2026 and The Belly Button on November 5, 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.*