# Fi vs Sleep Phase Tracker

The clearest difference is price: Fi at Free against Sleep Phase Tracker's $4.99. Fi also leads on ratings volume (42K vs 1) and chart position (#198 vs unranked). Sleep Phase Tracker's advantage is rating (5.0 vs 4.6) and iOS requirement (15.1 vs 17.0). On update cadence, ads, in-app purchases and device support there is nothing between them.

Fi is free to download; Sleep Phase Tracker costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Sleep Phase Tracker holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Fi has 42K ratings behind it against 1, so its average is the more settled of the two.

Fi ships an update weekly, Sleep Phase Tracker every 5 days. The most recent releases landed on October 24, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Fi | Sleep Phase Tracker |
| --- | --- | --- |
| Price | **Free** | $4.99 |
| Rating | [4.6 (42K ratings)](https://appshunter.io/ios/app/fi-gps-dog-tracker/id1438036784/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/sleep-phase-tracker/id6764618216/reviews)** |
| Number of ratings | **42K** | 1 |
| Positive reviews | 37.9% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Weekly | **Every 5 days** |
| Monetization | **Free** | Paid |
| Best chart rank | **#198** | — |
| Size | 199 MB | 31 MB |
| Requires iOS | 17.0 | **15.1** |
| Devices | **iPhone, iPad, Apple Watch** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Barking Labs Corp.](https://appshunter.io/developer/1002251935) | [MAXWELL JEREMIAH DROWN](https://appshunter.io/developer/1895851818) |

## What reviewers say

### Fi

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

**Currently charting:** #198 Top Free · Health & Fitness (US App Store)

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)


### Sleep Phase Tracker

[App page](https://appshunter.io/ios/app/sleep-phase-tracker/id6764618216)

This app guides users through a doctor-prescribed protocol to gradually shift their body clock earlier. It provides nightly reminders for bedtime, wake time, melatonin, and light therapy, while allowing users to log their sleep and track progress.

**Highlights:** Personalized protocol setup, Nightly bedtime and wake time guidance, Melatonin and light therapy reminders, Daily sleep logging, Streak tracking for progress, Customizable protocol adjustments

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

**In-app purchases:** none


## Frequently asked questions

### Is Fi free?

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

### Is Sleep Phase Tracker free?

Sleep Phase Tracker costs $4.99, with no in-app purchases.

### Which has better reviews, Fi or Sleep Phase Tracker?

Sleep Phase Tracker is rated higher. Fi averages 4.6 out of 5 from 42K ratings, while Sleep Phase Tracker averages 5.0 from 1 ratings.

### Do Fi or Sleep Phase Tracker have ads?

Neither Fi nor Sleep Phase Tracker shows ads.

### Which is updated more often, Fi or Sleep Phase Tracker?

Fi ships an update weekly, and Sleep Phase Tracker every 5 days. Most recently, Fi was updated on October 24, 2026 and Sleep Phase Tracker on October 8, 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.*