The personal evidence app — for iPhone

Find what actually improves your sleep.

The internet says what improves sleep in general. A tracker says how you slept. N of 1 answers the question that matters: what works for you? Run one research-backed experiment at a time — caffeine cutoff, morning daylight, screens off — and let your own mornings deliver the verdict.

Baseline first.·Then the change.·Your data decides.

Downloadon the App Store

First experiment free No account — 100% on-device No streaks, ever Cancel anytime

✓ Logged this morning Experiment · day 4/14 "Asleep before I finished my podcast."

Test sleep advice on the only person who matters: you

Every experiment in the library is grounded in published sleep research — and promises nothing. You log a few normal nights as your baseline, then make one change, and compare against your own normal. A 15-second check-in each morning is all it takes.

"I will have no caffeine after 12 PM for 14 days."

12 research-backed experiments — caffeine, daylight, wake time, alcohol, screens, temperature and more. Or design your own.

No streaks. No guilt. Just your own evidence.

Habit apps punish gaps. Scientists just note a data point and move on. Every experiment has a defined end date — nothing nags forever.

Today screen with a running sleep experiment and morning check-in button — A 15-second morningSleep quality, restedness, time to fall asleep.

Experiment detail with baseline and experiment phases on a neutral calendar — Baseline → experimentCompare against your own normal.

Result screen: You fell asleep faster on 13 of 13 experiment days — Helped, tested once — An honest resultPlain language, no made-up percentages.

"No clear effect" is a result too.

This app doesn't cheer you on — it tells you what your data says. Sometimes a change helps. Sometimes it does nothing, and knowing that saves you from running a habit that isn't yours. Retest any result to see if the effect repeats.

Helped No clear effect May have made it worse

What you get

12 research-backed experiments
Caffeine cutoff, morning daylight, wake time, alcohol-free nights, screens, temperature and more — each grounded in published studies.
Honest recommendations
Tell the app what your evenings look like — it suggests what fits, and says when an experiment probably isn't right for you.
Baseline → experiment
A few nights of normal life first, so your result is a comparison — not a guess.
A clear result
Helped, no clear effect, or may have made it worse — in plain language, from your own numbers.
My Sleep Playbook
Every result kept for good — your personal evidence, growing one experiment at a time.
Quiet reminders
One optional morning nudge. Never a guilt trip, never a missed-day shame banner.

🔒 Private by design

Everything stays on your device. No account. No cloud. No tracking.

Read the privacy policy — it's short.

Free & Pro — no surprises

Your first experiment is free — recommendation, baseline, check-ins, your result and the playbook included. The free experiment IS the trial: see whether your own evidence is worth building before paying anything.

Lab Pro from $2.99/month: keep experimenting — as many experiments as you want (one honest test at a time), retests, your full archive, and Markdown/CSV export. $19.99/year, or $49.99 once for lifetime. Cancel anytime — local App Store pricing may vary.

Test sleep advice on the only person who matters: you

No streaks. No guilt. Just your own evidence.

What you get

🔒 Private by design

Free & Pro — no surprises

What will you test first?