# Fi vs Function Health

The clearest difference is monetization model: Fi at free against Function Health's subscription. Fi also leads on device support (3 vs 1). Function Health's advantage is review sentiment (62% vs 38%) and rating (4.9 vs 4.6). On price, ratings volume, update cadence and ads 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 4.6. Both are backed by a comparable volume of ratings — 42K and 25K respectively. Written reviews point the same way: 38% of Fi's written reviews are positive against 62% of Function Health's.

Both ship on a similar rhythm, roughly weekly. Both last shipped on October 21, 2026.

## The numbers

| Metric | Fi | Function Health |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.6 (42K ratings)](https://appshunter.io/ios/app/fi-gps-dog-tracker/id1438036784/reviews) | **[4.9 (25K ratings)](https://appshunter.io/ios/app/function-health/id6471280307/reviews)** |
| Number of ratings | **42K** | 25K |
| Positive reviews | 37.9% of reviews | **61.8% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | Weekly |
| Monetization | **Free** | Subscription |
| Best chart rank | — | **#191** |
| Size | 197 MB | 203 MB |
| Requires iOS | 17.0 | **16.4** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone |
| Age rating | 4+ | 17+ |
| Developer | [Barking Labs Corp.](https://appshunter.io/developer/1002251935) | [Function Health](https://appshunter.io/developer/1715014524) |

## What reviewers say

### Fi

[App page](https://appshunter.io/ios/app/fi-gps-dog-tracker/id1438036784)

This app pairs with a smart collar to provide real-time GPS tracking for your dog. Monitor their activity, health patterns, and receive alerts if they leave designated safe zones. It offers peace of mind for pet owners by keeping them connected to their canine companions.

**Highlights:** Real-time GPS tracking, Geofencing and escape alerts, Activity and health monitoring, AI behavior insights, Lost Dog Mode, Long battery life, Apple Watch integration

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Accurate GPS tracking
- 🔒 Provides peace of mind
- 👍 Helpful customer service
- 🚀 Long battery life
- 👍 Waterproof collar

**What reviewers complain about**

- 🐛 Inaccurate GPS location
- 🔋 Battery drain issues
- 🐛 Unreliable connectivity
- 👎 Intrusive notifications
- 👎 Difficult to cancel subscription

**Reported bugs**

- Collar stops working unexpectedly
- App glitches and crashes
- GPS tracking lags or shows incorrect locations

**Requested features**

- Customizable notification settings
- Offline step/distance tracking
- Ability to edit/delete activity data
- More accurate geofencing options
- Integration with other apps (e.g. Wag)


### Function Health

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

**Currently charting:** #191 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 Fi free?

Fi 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, Fi or Function Health?

Function Health is rated higher. Fi averages 4.6 out of 5 from 42K ratings, while Function Health averages 4.9 from 25K ratings.

### Do Fi or Function Health have ads?

Neither Fi nor Function Health shows ads.

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

Fi ships an update weekly, and Function Health weekly. Most recently, Fi was updated on October 21, 2026 and Function Health on October 21, 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.*