# Sunlighten vs Function Health

The clearest difference is review sentiment: Function Health at 62% against Sunlighten's 19%. Function Health also leads on rating (4.9 vs 2.8) and update cadence (weekly vs every 4 months). Sunlighten's advantage is monetization model (free vs subscription) and device support (3 vs 1). On price, ads, in-app purchases and iOS requirement there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Function Health holds the better App Store score, 4.9 against 2.8. That said, the two scores are not equally well evidenced: Function Health has 25K ratings behind it against 77, so its average is the more settled of the two. Written reviews point the same way: 19% of Sunlighten's written reviews are positive against 62% of Function Health's.

Sunlighten ships an update every 4 months, Function Health weekly. The most recent releases landed on October 11, 2026 and October 16, 2026 respectively.

## The numbers

| Metric | Sunlighten | Function Health |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [2.8 (77 ratings)](https://appshunter.io/ios/app/sunlighten/id1634410434/reviews) | **[4.9 (25K ratings)](https://appshunter.io/ios/app/function-health/id6471280307/reviews)** |
| Number of ratings | 77 | **25K** |
| Positive reviews | 19.0% of reviews | **62.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Weekly** |
| Monetization | **Free** | Subscription |
| Best chart rank | — | **#205** |
| Size | 53 MB | 202 MB |
| Requires iOS | **15.1** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 17+ | 17+ |
| Developer | [Sunlighten Inc](https://appshunter.io/developer/1634410436) | [Function Health](https://appshunter.io/developer/1715014524) |

## What reviewers say

### Sunlighten

[App page](https://appshunter.io/ios/app/sunlighten/id1634410434)

Optimize your well-being with this app, designed to enhance your light therapy and sauna experiences. Create personalized wellness programs, track sessions in real-time, and control your devices remotely for a seamless health journey.

**Highlights:** Science-based wellness programs, Personalized program creation, Real-time session tracking, Remote sauna control (Wi-Fi), Audio and lighting management, Red light therapy panel programs

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Convenient remote control
- 👍 Customizable programs
- 🚀 Easy to use app
- 👍 Enhances sauna experience

**What reviewers complain about**

- 🐛 Unreliable app connectivity
- 🔒 Privacy concerns with data collection
- 🐛 Inconsistent scheduling and remote start
- 🐛 Buggy and glitchy app
- 👎 Limited remote functionality

**Reported bugs**

- App fails to connect to sauna
- Scheduled programs not running as expected
- Inconsistent lighting controls
- Tablet frequently restarts or loses connection

**Requested features**

- Remote start and preheat capability
- Improved app stability and reliability
- Better integration between app and sauna
- More customization options


### Function Health

[App page](https://appshunter.io/ios/app/function-health/id6471280307)

**Currently charting:** #205 Top Free · Health & Fitness (US App Store)

Take control of your health with comprehensive lab testing, personalized protocols, and AI-powered insights. Understand your body's data, track changes over time, and make informed decisions for long-term wellness. Connect wearables and upload records for a complete health picture.

**Highlights:** 160+ lab tests annually, Personalized health protocols, Private AI Chat for results, Connect health wearables, Advanced MRI & CT scans, Upload health records

**Features:** Apple Wallet

**In-app purchases:** none

**What reviewers like**

- 🚀 Seamless process for blood tests and results
- 📊 Comprehensive health insights and tracking
- 🧠 Helpful clinician notes and recommendations
- 👍 User-friendly and visually appealing app
- 💰 Affordable compared to other options

**What reviewers complain about**

- 🔍 Lack of communication and support responsiveness
- 🐛 Some bugs and usability issues in the app

**Reported bugs**

- App sometimes redirects back to the home screen when trying to view results
- Occasional typos and formatting issues in the app

**Requested features**

- More customization options in the app settings
- Ability to print or export test results and recommendations
- Specific supplement recommendations rather than broad suggestions


## Frequently asked questions

### Is Sunlighten free?

Sunlighten is free to download, with no in-app purchases.

### Is Function Health free?

Function Health is free to download, with no in-app purchases.

### Which has better reviews, Sunlighten or Function Health?

Function Health is rated higher. Sunlighten averages 2.8 out of 5 from 77 ratings, while Function Health averages 4.9 from 25K ratings.

### Do Sunlighten or Function Health have ads?

Neither Sunlighten nor Function Health shows ads.

### Which is updated more often, Sunlighten or Function Health?

Sunlighten ships an update every 4 months, and Function Health weekly. Most recently, Sunlighten was updated on October 11, 2026 and Function Health on October 16, 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.*