Sleep debt
Clear
Down 30m
Your last 14 nights are tracking your goal. Keep the rhythm steady. No makeup sleep needed.
Built around sleep debt.
Mendtide’s recovery indicator is one number: the running deficit between the sleep you got and the sleep your body needs, summed across your last 14 nights. Every other metric — HRV, duration, consistency, your wake events, your context tags — feeds into it or explains it. Train hard and the need itself rises, because bigger efforts ask for more recovery.
Each night’s surplus caps at two hours. A twelve-hour Saturday doesn’t repay a week of short nights — recovery is non-linear, and we’d rather the number reflect that than tell a comforting lie.
We never display the debt as a red number. Recovery clears over weeks, not nights. The point is the trajectory you’re on, not a score that ranks you.
Sleep debt
1h 04m
Down 32m
Built up across the last two weeks. Hitting your goal tonight chips away at it; you don’t need to sleep extra to repay.
14-day rolling window. Recovery clears over weeks,
not nights.
Sleep debt
Building your baseline
We’ll start tracking your debt once we have a full week of nights on file. Until then, focus on hitting your goal one night at a time.
10:32 PM
You go to bed
Apple Health is already tracking your sleep. Mendtide picks up your bedtime the moment your Watch or iPhone notices you’ve stopped moving for long enough to count.
No alarm to set. No I’m going to bed button. Just open the app whenever you wake up. Last night is already there, ready to be read.
10:32 PM
Mendtide reads from Apple Health while you sleep. No alarm to set, no “I’m going to bed” button.
Apple Health Mendtide
3:14 AM
You wake at 3 AM
Most sleep trackers double down at 3 AM. They show you a score, an unflattering debt count, a graph of your wreck of a night. The research on this is settled: that’s how you make insomnia worse.
Mendtide refuses. The Journal tab is right there if you need to empty your head, and that’s it. No graphs. No metrics. No panic. Tomorrow morning is still on its way.
Journal
Empty your head. Nothing here is analyzed.
Start writing…
6:48 AM
You wake up to the summary
A gradient progress bar shows last night vs your goal at a glance. Below it, your 14-day sleep debt, trending down or up, no graph required to read it.
Then a short list of things to actually do today: when to get sunlight, when to cut caffeine, when to wind down tonight. Each one cites the night that produced it and the research that backs it.
Tuesday morning
Last night’s stats
7 hours
100%
Sleep debt
Clear
Your last 14 nights are tracking your goal. Keep the rhythm steady. No makeup sleep needed.
Throughout the day
Ask Mendtide anything
The coach knows your last 14 nights. It knows whether your kid woke you, whether you had a hot flash, whether you worked out late, whether you drank, whether you were travelling. It also sees your workouts, how hard you trained, and your caffeine timing, pulled straight from Apple Health, not guessed.
Ask why your sleep is fragmented, why your HRV dropped, whether melatonin is worth trying. Answers cite your actual data, not the same generic blog post every other sleep app is paraphrasing.
Coach
Ask anything about your sleep.
Why have I felt off all week?
You woke up 3 times last night, once at 3:14 AM. Two of those
line up with nights you marked as the kid waking you up.
Worth checking room temperature tonight? You’ve also been logging later workouts on the same days.
Worth checking room temperature tonight? You’ve also been logging later workouts on the same days.
Ask about your sleep
Over weeks
Real change shows up here
Mendtide tracks your recovery and your movement over time. Recovery: HRV, resting heart rate, sleep duration, and consistency. Movement: steps, workouts, exercise minutes, and VO2 max. Each gets its own card you can long-press for the research behind the number you’re looking at.
Single nights are noisy. Everyone has bad ones. What moves on the trend view is the thing actually worth changing for: the pattern across weeks.
Recovery
Trends, not single nights.
HRV
52 ms ↑ 3
RHR
58 bpm ↓ 2
Sleep duration
6h 58m
Consistency
81 %
Steps
8,240 ↑
VO2 max
41 ml/kg ↑
Built for nights that don’t fit the textbook.
For new parents
Fragmented sleep, 3 AM wake-ups, a year you don’t quite sleep through. Mark a night as the kid waking you up and tomorrow’s plan adapts, so the advice you get reflects the night you actually had, not an idealized one.
For perimenopausal nights
Hot flashes, night sweats, hormonal disruption no generic tracker accounts for. Tap a hot flash or a night sweat on last night’s entry and Mendtide adjusts its read of your data + its coaching to match the night you had.
One plan. Every feature. 14 nights free.
Mendtide doesn’t gate features behind tiers. The plan you start with is the plan that does everything.
Monthly
$9.99 /mo
Annual
Save 42%
$69.99 /yr
$5.83/mo equivalent
14 nights, full access. Cancel anytime in Settings. No
ads, no trackers. Subscription renews monthly or annually
depending on the plan you choose at the end of the trial.
- Apple Health sleep + recovery ingest
- 30-second morning briefing, every day
- AI coach with your 14-night history
- Editable sleep history + context tags
- Recovery trends: HRV, RHR, duration, consistency
- Journal: empty your head at 3 AM
- No ads. No tracking. No data resale.
The questions that come up most.
Is Mendtide free?
14 nights free. After the trial, $9.99 per month or $69.99 per year. Every feature is on every plan, with no premium tier. The trial is full-fat access, not a teaser.
Do I need an Apple Watch?
No. Mendtide reads from Apple Health on your iPhone. If you own an Apple Watch, the Watch's native sleep tracking writes to Health and Mendtide picks it up. iPhone-only users get every feature; the phone auto-detects sleep from motion + screen activity.
Is my data private?
Yes. Raw HealthKit data never leaves your device by default. The AI coach receives anonymized, aggregated summaries: heart rate variability ranges, sleep duration averages, activity and caffeine totals, and your context tags. Never raw biometric samples. No third-party trackers, no ad networks, no data resale.
Does Mendtide work for fragmented sleep?
Yes. That's what it was built for. New parents, perimenopausal users, shift workers, frequent travelers, anyone whose sleep doesn't fit a textbook 8-hour block. You can tag a night with the context that shaped it, like a kid waking you, a hot flash, a late workout, alcohol, illness, or travel, and the recommendations and coach answers adapt to match the night you actually had.
What happens if I open the app at 3 AM?
You see the regular app, including the Journal tab, a quiet place to write down whatever's keeping you up. No sleep score, no debt count, no graph. Mendtide deliberately doesn't show metrics at 3 AM because the research is clear: sleep tracking at vulnerable moments feeds anxiety, not recovery.
Does Mendtide give me a sleep score?
No 0 to 100 number in the default UI. Sleep scores reliably trigger orthosomnia, the sleep anxiety driven by chasing an arbitrary metric. Mendtide uses qualitative framing instead: "A solid night," "A short night," with the actual hours and recommendations alongside. Advanced users can opt into numeric views in Settings.
Can I correct my sleep history?
Yes. One tap on any night marks it as wrong, and you can edit bedtime, wake time, or add context tags. The rule engine and the AI coach both adapt to your corrections, so the model gets more accurate as you tell it what actually happened.
Will the AI coach give me medical advice?
No. The coach can describe research findings, suggest lifestyle adjustments, and recommend talking to a doctor. It will never diagnose a condition, prescribe a medication, recommend stopping a prescription, or contradict medical guidance from a clinician. Crisis-related questions route to the 988 Suicide & Crisis Lifeline immediately.