Comparison

Fi vs Sleep Phase Tracker

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Fi

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
Read full description

Fi Series 3+ is the world's smartest GPS dog collar—now powered by AI. Paired with a Fi collar, the Fi app brings you even closer to your dog. Track their location, monitor activity and health patterns, and get alerts if they ever leave a safe zone. It's peace of mind for the best pet parents out there. FEATURES GPS TRACKING On vacation? Friend walking the dog? Instantly track your dog's location no matter where they are. Fi gives you the confidence to know they're safe from anywhere, anytime. STOP ESCAPE ARTISTS Designate safe zones around your home or dog's favorite places. If they leave without a trusted person, we'll alert you immediately. So if they wander anywhere, you'll be the first to know. ACTIVITY MONITORING Track your dog's step count daily and start streaks by achieving custom goals you set. Then see how they compare with similar dogs in the Fi community. Every step goes a long way toward keeping them happy and healthy. AI BEHAVIOR INSIGHTS Fi Series 3+ tracks more than just steps. Spot trends in activity, rest, scratching, licking, drinking, eating, and barking so you can stay in tune with your dog's health and habits, every day. LOST DOG MODE Never lose track again. If your dog goes missing, activate Lost Dog Mode to turn on rapidly refreshing live location updates until they're found. BATTERY LIFE With best-in-class battery, our collars lasts up to 3 months on a single charge. No other collar even comes close. SUPPORT Need help? We're here for you and your dog. Our support team is just a chat or phone call away when you need. APPLE WATCH INTEGRATION With our all new Series 3+, you can view your dog's location and activity directly on your wrist, so you're always connected, even without your phone. OUR COLLAR Available in 4 different colors and 5 different sizes to fit dogs of all sizes. Fi works best when connected near a Bluetooth connected device with the Fi App or the provided charging base. The latest iOS version is required to run Fi. Learn more about what we're building at: www.tryfi.com.

About

Sleep Phase Tracker

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
Read full description

SleepPT helps you follow your doctor's delayed sleep phase protocol — the gradual, week-by-week process of shifting your body clock earlier. Set up your personalized protocol once, then let the app guide you every night with your current bedtime, wake time, melatonin reminder, and light therapy cues. Log each morning, track your streak, and advance through your schedule at your own pace. FEATURES - Tonight's plan — bedtime, wake time, melatonin, and dim-lights times at a glance - Daily sleep log — track actual times, medications, sleep quality, and notes - Streak tracking — 7 consecutive on-time mornings earns a week advance - Progress view — see your full protocol at a glance, week by week - Missed night support — gentle, non-judgmental flow for nights you miss - Customizable protocol — adjust start/goal times and advance step if your doctor prescribed different values - Dark mode support - No account required — all data stays on your device Built for people managing Delayed Sleep Phase Syndrome (DSPS) with a doctor-prescribed chronotherapy protocol.

Screenshots

Fi4 screens
Sleep Phase Tracker4 screens

Verdict

The call

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 (#195 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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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.

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

Fi ships an update weekly, Sleep Phase Tracker every 5 days. The most recent releases landed on October 23, 2026 and October 8, 2026 respectively.

Scorecard6 real differences · 5 level
Fi versus Sleep Phase Tracker: the parameters behind the verdict, then further details
ParameterFiSleep Phase Tracker
PriceFree — better$4.99
Rating4.6 (42K ratings)5.0 (1 ratings) — better
Positive reviews37.9% of reviews—
Number of ratings42K — better1
Update frequencyWeeklyEvery 5 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank#195 — better—
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPod
Requires iOS17.015.1 — better
Further details — not scored
Size199 MB31 MB
Age rating4+17+
DeveloperBarking Labs Corp.MAXWELL JEREMIAH DROWN

Customer experience

Fi

All ratings41,764 ratings
Positive91.2%
Neutral2.7%
Negative6.1%
Written reviews649 reviews
Positive37.9%
Neutral12.2%
Negative49.9%

Sleep Phase Tracker

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Fi

Reported bugs

3 issues
  • Collar stops working unexpectedly
  • App glitches and crashes
  • GPS tracking lags or shows incorrect locations

Requested features

5 requests
  • 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

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Fi

No in-app purchases

None

Sleep Phase Tracker

No in-app purchases

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 23, 2026 and Sleep Phase Tracker on October 8, 2026.

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