# UV Index vs HydroLoop

The clearest difference is rating: HydroLoop at 5.0 against UV Index's 1.0. On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. UV Index sells 2 in-app purchases, starting at $12.99 per year and HydroLoop sells 2 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

HydroLoop holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 1 and 2 respectively.

UV Index ships an update every 3 weeks, HydroLoop monthly. The most recent releases landed on October 28, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | UV Index | HydroLoop |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [1.0 (1 ratings)](https://appshunter.io/ios/app/uv-index-sundoze/id6770479402/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/hydroloop-water-tracker/id6782740767/reviews)** |
| Number of ratings | 1 | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Monthly |
| Monetization | Freemium | Freemium |
| Size | 7 MB | 5 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | **iPhone, Apple Watch** | iPhone |
| Age rating | 4+ | 12+ |
| Developer | [Liridon Tahiraj](https://appshunter.io/developer/1823885577) | [MALCOLM VINCENT GERARD](https://appshunter.io/developer/6782740769) |

## What reviewers say

### UV Index

[App page](https://appshunter.io/ios/app/uv-index-sundoze/id6770479402)

This app provides personalized sun exposure guidance based on your skin type, location, and altitude. It offers modes for maximizing vitamin D or minimizing sun damage, with features for travel and winter conditions.

**Highlights:** Personalized sun exposure based on skin type, location, and altitude, Modes for vitamin D, tanning, or sun protection, Travel mode for comparing UV index across locations, Altitude correction for UV intensity, Winter mode for vitamin D tracking, Burn time calculation using Fitzpatrick scale

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Sundoze Pro Yearly | $12.99 | per year |
| Sundoze Pro Lifetime | $29.99 | one-time |


### HydroLoop

[App page](https://appshunter.io/ios/app/hydroloop-water-tracker/id6782740767)

This app gamifies hydration by letting you watch a 3D bottle fill with each sip. It offers personalized daily goals, tracks various beverages, and uses streaks to motivate users. Syncs with Apple Health and provides widgets for easy access.

**Highlights:** Living 3D bottle visualization, Personalized daily hydration goals, Streak tracking and rewards, Logging of various beverage types, Apple Health integration, Home/Lock Screen widgets

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| HydroLoop+ Monthly | $1.99 | per month |
| HydroLoop+ Lifetime | $19.99 | one-time |


## Frequently asked questions

### Is UV Index free?

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

### Is HydroLoop free?

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

### Which has better reviews, UV Index or HydroLoop?

HydroLoop is rated higher. UV Index averages 1.0 out of 5 from 1 ratings, while HydroLoop averages 5.0 from 2 ratings.

### Do UV Index or HydroLoop have ads?

Neither UV Index nor HydroLoop shows ads.

### Which is updated more often, UV Index or HydroLoop?

UV Index ships an update every 3 weeks, and HydroLoop monthly. Most recently, UV Index was updated on October 28, 2026 and HydroLoop 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.*