No Watch Required
Sleep Tracker for iPhone — No Apple Watch Needed
Snollo uses your iPhone's microphone and on-device AI to detect snoring, sleep sounds, and sleep quality — overnight, in your bedroom, without a watch on your wrist.
Apple Watch is optional — pair one later if you want heart rate and detailed REM/Deep/Light stages. The iPhone-only mode is fully functional from night one.
Download Free — iPhone OnlyiPhone · iOS 17+ · Apple Watch optional
Why you don't need an Apple Watch to track sleep
The microphone catches what a watch can't
Snoring, sleep talking, coughing, breathing pauses — these are audio events. An Apple Watch's accelerometer and heart-rate sensor can't detect them. The iPhone's microphone can, and Snollo's on-device AI classifies what it hears in real time.
Apple Watch battery dies during long nights
Many Apple Watch owners take the watch off to charge before bed. If you wear it to sleep, you wake up to find it low — and you've still missed sleep tracking on the nights you forgot. The iPhone on your nightstand doesn't have that problem.
Most people don't want a watch on at night
Wearing anything on your wrist while you sleep is a personal preference. Skin sensitivity, side sleepers, partners who don't like the light from the screen — there are real reasons to skip the watch. Sleep tracking shouldn't require a $400 wearable purchase.
An iPhone alone is more than enough
Snollo's iPhone-only mode tracks duration, detects sound events with timestamps and audio clips you can play back, calculates a nightly sleep quality score, and shows weekly trends. Apple Watch adds REM/Deep/Light stage detail and heart rate context — useful, but not essential.
How iPhone-only sleep tracking works
What happens between "tap Start before bed" and "open the report in the morning."
- 1
Tap Start, place the iPhone within arm's reach
Tracking does not begin until you explicitly tap Start. Place the iPhone face-down on the mattress beside you or on a nightstand within 1–2 meters of your head. Keep it plugged in. Lock the screen — Snollo runs in the background using iOS's audio recording entitlement.
- 2
The microphone records ambient sound overnight
Your iPhone's microphone captures the soundscape in your room. The audio exists only in the device's working memory while Core ML processes it — frame by frame — into classifications.
- 3
Core ML classifies each sound on-device
Apple's Core ML framework runs Snollo's audio classification model on the iPhone's Neural Engine. Every few seconds, it labels what it heard — silence, snoring, breathing, coughing, talking — with a confidence score. The raw audio is then discarded.
- 4
Short clips of detected events are saved
When Snollo detects a notable sound (a snore, a cough, sleep talking), a short clip is saved to your private iCloud container so you can play it back in the morning. The bulk of the night — silence — is never written anywhere.
- 5
In the morning, you get a full report
Tap to view your sleep duration, sound timeline, snore intensity over time, and a sleep quality score. Optional Apple Watch pairing later adds REM/Deep/Light stages, heart rate, and SpO₂ — all data automatically merges with your existing sound timeline.
iPhone Sleep Tracker Comparison
Which iOS sleep apps work without an Apple Watch — and what they cost.
| App | iPhone-only mode | With Apple Watch | Account | Price |
|---|---|---|---|---|
| Snollo ★ | Full features | REM/Deep/Light, HR | Not required | Free + optional Premium |
| SnoreLab | Full features | Not supported | Optional | $3.99/mo Premium |
| Sleep Cycle | Full features | Limited (HR) | Required | $39.99/yr |
| Pillow | Limited (paid) | Better experience | Required (Premium) | Free + $4.99/mo |
| AutoSleep | Not supported | Required | Not required | $3.99 one-time |
Based on publicly available App Store listings as of May 2026. Pricing reflects US App Store at time of writing.
If you also want…
Watch users
Apple Watch sleep tracking
REM/Deep/Light stages, heart rate, SpO₂ — what you get when you add a watch.
Privacy focus
The most private sleep tracker
How on-device audio processing keeps your bedroom recordings off other people's servers.
Snoring concern
Sleep apnea risk test
Free, validated STOP-BANG questionnaire — 60 seconds, no email required.
From the Snollo blog
Guide
REM, Deep, and Light Sleep — What Each Stage Does and How to Get More
A 5-minute primer on the four sleep stages. What REM, Deep, and Light sleep each do for your brain and body, how much of each you should get, and how to track them on iPhone or Apple Watch.
Guide
How Accurate Is Apple Watch Sleep Tracking? (What the Research Shows)
Apple Watch identifies light sleep with 86% sensitivity, REM with 82%, and deep sleep with 50–62% compared to polysomnography. Here's what the peer-reviewed research actually says — and what it means for your data.
Guide
Why You're Still Tired After 8 Hours of Sleep (And How to See What's Actually Happening Tonight)
Eight hours in bed isn't the same as eight hours of restorative sleep. Here are the seven evidence-based reasons you wake up exhausted — and how to collect your own sleep data tonight, privately, without a clinic visit.
iPhone Sleep Tracking — FAQ
Can I track sleep with just my iPhone, no Apple Watch?
Is iPhone-only sleep tracking accurate?
Where should I place my iPhone for sleep tracking?
What sleep trackers don't need an Apple Watch?
Will tracking sleep on iPhone drain the battery?
Does iPhone-only sleep tracking record everything I say?
Track your sleep tonight — iPhone only
Free download. No watch required. No account, no servers, no audio uploaded.
Download Snollo FreeiPhone iOS 17+ · Apple Watch optional · Free to download