Ledger
14-night ledger
Every night is a row: duration, delta, source. Deposits above the line, withdrawals below. Calendar gaps show as dashed rows, not silently vanished data.
Available on iOS
A piggy bank for your sleep debt.
Sleep debt tracker for iPhone and Apple Watch.
Save your sleep · Pay it back.
Short nights withdraw. Good nights deposit. Pennie totals your 14-night balance from Apple Health and walks you through a quiet Sunday ritual to catch back up.
iOS 17+ · HealthKit-native · On-device only · Not a medical device
The idea
A bank statement for your sleep.
Each night is a row. Deposits above the line, withdrawals below. Under the hood it's the Borbély two-process model and Van Dongen's rolling math. On the surface it's just Pennie, a gauge, and a ledger.
Works for the 9-to-5 and the 11-to-7. Patterns, not predictions. Warmth, not guilt.
Inside the app
Eight beats. One quiet ritual.
A look at every screen. Tap any to enlarge.
On the books
14 nights, ledgered.
Every night Pennie reads from Apple Health gets its own row. Duration, target, delta, source. The headline number is the sum of the last 14. Older nights age out as new ones land.
Every night, a row
minutes vs target
14 nights agolast night
14-night balance
0h 00m
A little in the red, but climbing.
- Best night+1h 30m
- Worst night−1h 40m
- Avg / night−19m
This week
Zoom in on the last seven.
Same ledger, focal week. The Sunday ritual works from this view. Review where you slipped, pick a pace, let Pennie file tomorrow's bedtimes into your calendar.
This week
−2h 15m
MTWTFSS
7h 05m7h 50m6h 35m8h 30m6h 20m10h 10m7h 15m
Tonight's tune-up
“Friday hit you hard. Aim for 8h 30m and skip the 4pm coffee.”
One to three small nudges a day, drawn from this week's shape. Dismiss a card and it won't re-ask for three days. Warmth, not nagging.
Sources this week
- Apple Watch5 nights
- iPhone bedtime2 nights
The science
The math, in plain English.
Process S climbs with every waking hour. The homeostatic drive. Process C oscillates with your circadian clock. Their interaction is what your gauge tracks.
Same math as Borbély 1982 and Van Dongen 2003. Borrowed, not invented. We just rendered it as a piggy bank.
Read the full methodology →Process S· homeostaticProcess C· circadian
Forecast
Patterns, never predictions.
Pennie shades darker where you've historically run low. The post-lunch dip, the pre-bed wind-down, the Thursdays that always sting.
Built from your last 28 nights. Every cell is a pattern from your own history. Never a confidence percentage, never a “you will crash” claim.
Typical-dip heatmap
7 days × 24 hours · likelihood, not prediction
12a
6a
9a
12p
3p
6p
9p
Mon
Tue
Wed
Thu
Fri
Sat
Sun
typical dip likelihood
sleep window
What's inside
Everything a quiet sleep tracker should be.
Forecast
Typical-dip heatmap
A 7-day by 24-hour view of where your energy historically dips. Built from your last 28 days. Pattern-language only. Never a 'you will crash' claim.
Ritual
The Sunday ritual
Five quiet steps every Sunday. Review the week, pick a pace, let Pennie file the bedtimes into your calendar. Becomes the anchor of a healthier rhythm.
Advice
Tonight's tune-up
One to three small nudges a day. 'Tonight, aim for 8h 30m.' 'Thursdays tend to be rough.' 'Skip the nap today.' Dismiss any card; it won't re-ask for three days.
Edge states
Warmth when it's hard
Five days of deep debt aren't met with a red alert. Pennie gets quieter, offers a gentler plan, and respects a snooze button. The app knows when to step back.
Share
Weekly statement, reel-worthy
Tap the gauge on Sunday and you get a five-second vertical clip of your week: balance, best night, typical dip, Pennie's line. Strava-grade restraint. No branded loudness.
Bonus
A glance at your wrist
The Apple Watch app and complication keep the balance one wrist-flick away. Optional. The iPhone app is the home for the full ledger and the Sunday ritual.
Privacy
Your sleep stays on your phone.
No cloud sync. No server copy. Analytics is strictly opt-in and only ever carries event names. Never numbers. If you uninstall the app, every night goes with it.
Read the privacy page →- ✓Reads sleep from Apple Health on your device.
- ✓No CloudKit sync (App Store §5.1.3 compliant).
- ✓Crash reports scrub any sleep-related values before send.
- ✓Analytics defaults off. You turn it on if you want.
- ✓HealthKit access revokable anytime from iOS Settings.
all on your phone
HealthKit
Apple Health on your device
Pennie's math
two-process · 14-night sum
Your ledger
every night, every delta
The gauge
one warm number
What it costs
Two plans. Cancel anytime.
Install for free and you get the full 14-night ledger, your first Sunday ritual, manual entry, and a weekly advice card from Pennie. No card needed to try it.
Monthly
$3.99/ month
Billed monthly. No trial. Cancel from iOS Settings anytime.
- ✓ Forecast and Repayment Plan
- ✓ All six widgets, share card, watch app
- ✓ Bedtimes saved to your Apple Calendar
- ✓ Daily nightly tune-ups
14-day free trial
Annual
$34.99/ year
Under $3/mo billed yearly. Saves 27% vs monthly. Family Sharing on.
- ✓ Everything in Monthly
- ✓ 14-day free trial, no card charged if you cancel
- ✓ Share with up to 5 family members
- ✓ Long enough for two Sunday rituals
Prices shown in USD; your local currency appears at checkout. See the full terms of use for auto-renew disclosure, or the support page for cancellation and refund questions.
Save your sleep · Pay it back.
Pennie is open for business
Open the books tonight.
Free to install. The full 14-night ledger and your first Sunday ritual are yours without paying. Try the whole thing once, then decide.
Stay in the loop
One email when there's news worth your inbox.
No feed. No follow-ups. Just the milestones: Android plans, major updates, the rare price change.