The nightly view
“How did I sleep?”
A score, last night’s duration, and stage breakdown help explain one sleep session.
Sleep debt, made visible
A good night can hide a bad trend.
Sleep scores tell you how last night went. Somnus shows what all those nights add up to—your shortfall, your running balance, and how serious the debt has become.
Now on the App Store for iPhone and iPad, using Apple Watch sleep data
- PlatformiOS 17+
- App StoreAvailable
- LicenceMIT
Snapshot vs trajectory
The difference is the question.
Apple Health gives you rich sleep history: duration, stages, scores, and trends. Somnus uses that same on-device sleep data to answer a different question—how far behind your personal sleep target are you becoming?
The Somnus view
“What is it adding up to?”
Nightly shortfalls become a running ledger, exposing a deficit that can be easy to miss one morning at a time.
See the debt build
One story. Three views.
The screenshots use deterministic sample data. They show why a perfectly good night can coexist with a pattern that deserves attention.
1
Start with the contradiction
Last night scored 94. The week is still 4.6 hours behind. Both can be true.
2
See every contribution
Orange bars show each night’s shortfall. The purple line turns separate misses into one running total.
3
Zoom out before you dismiss it
A manageable nightly gap becomes an 18-hour monthly deficit. Somnus can scale the same view from a day to ten years.
A simple ledger
Your target minus your sleep.
Somnus totals the shortfall for every tracked night in the selected period. Fragmented sessions are merged, and nights with no recorded sleep are excluded—missing data never becomes phantom debt.
Personal target
8.0 hours
Sleep recorded
6.5 hours
That night adds
1.5 hours debt
Private by design
Your sleep stays yours.
Somnus requests read-only access to sleep analysis in Apple Health. Calculations happen on your device, with no account, analytics, advertising, or developer-operated server.
Read-only Health access
On-device calculations
No ads or tracking
No Health data uploads
Under the hood
Native, and open.
Somnus is a SwiftUI app built directly on HealthKit and Swift Charts, with no third-party SDKs. The sleep-debt engine and its unit tests are published under the MIT licence, so the numbers on screen can be checked against the code that produced them.
- SwiftUI
- HealthKit
- Swift Charts
- Combine
- PlatformiOS 17+
- LanguageSwift 5.9
- LicenceMIT
- App StoreAvailable
- Version1.0.0
- Privacy100% on-device
- Devices
- iPhone and iPad
- Data source
- Apple Watch sleep tracking, read from Apple Health
- Health access
- Read-only Sleep Analysis
- Network use
- None — no accounts, servers, or analytics
Look beyond last night
See what your sleep is adding up to.
Somnus is now on the App Store. Download it to see your sleep debt, or explore the source and get in touch with questions.