Stop guessing which habits are working
Find out which habits actually change how you feel
Most trackers show you streaks. Crescendo runs the statistics on your own data and names the relationships it finds — better sleep to better training, morning meditation to tomorrow's mood — with the numbers behind each one.
Free to start. No card, and your journal is never used to train anything.
- analytics tests, against known answers
- 100analytics tests, against known answers
- Bonferroni-corrected significance floor
- p ≤ 0.00625Bonferroni-corrected significance floor
- WCAG contrast checks, both themes
- 78WCAG contrast checks, both themes
- journal entries used for advertising
- 0journal entries used for advertising
What it does
Six things most habit trackers get wrong
Each of these is a decision with a reason behind it, not a feature list.
Habits that forgive a bad week
A day counts at 60% of its expected load, not 100%. A habit due four days a week only asks for four. Six of eight glasses of water is 0.75 of that habit, not a failure. Streaks you can actually keep.
Read moreSleep, in stages
Duration, deep, REM, light and awake, with bedtime consistency tracked separately — because when you go to bed predicts more than how long you stay there. Ready for Apple Health and Health Connect.
Read moreA journal that stays yours
Morning intentions, evening reflections, and an AI that reflects on what you wrote. The text never leaves your account — not to an ad platform, not into a training set, not into our own dashboards.
Read moreStatistics, not vibes
Pearson and point-biserial correlations with exact t-distribution p-values. A finding appears only if it clears three floors at once: 20 paired days, |r| ≥ 0.25, and a corrected p ≤ 0.00625.
Read moreHonest about nothing
The hypotheses are fixed in advance rather than trawled, so "nothing to report" is a real outcome the screen is designed to show. Every card carries its r and its sample size.
Read moreCalm by construction
No streak-loss guilt, no red badges, no notification you did not ask for. Every colour in the interface was contrast-solved rather than eyeballed, in both light and dark.
Read more
What you actually see
Your day, then the pattern behind it
Two screens carry the product. Today is what you open in the morning. Insights is what you read at the end of a month.
Today
Whole habits finished, so the ring always agrees with the checkmarks.
Insights
Every claim about your life arrives with the evidence for it.
Better sleep, more training
r = 0.41 · n = 118 · p < 0.001On nights over 7h 20m you trained on 71% of the following days, against 34% otherwise.
Morning meditation lifts tomorrow
r = 0.29 · n = 104 · p = 0.003Mood averaged 0.5 higher the day after you sat, controlling for sleep.
Illustrative figures from the demo dataset — the same ones the seeded history produces, and the same filters your own data passes through.
How it differs
Compared with a typical habit tracker
Behaviours rather than brands, so you can check each one yourself.
| Capability | Crescendo | Typical |
|---|---|---|
| Streaks that survive one missed day | Yes | No |
| Partial credit on numeric targets | Yes | No |
| Correlations with p-values and sample sizes | Yes | No |
| Pre-registered hypotheses, not data trawling | Yes | No |
| Sleep stages alongside habits | Yes | Varies |
| Journal text excluded from all analytics | Yes | No |
| Full data export and deletion, self-service | Yes | Varies |
| Contrast-audited in light and dark | Yes | No |
Pricing
One paid tier, priced like a coffee
The free plan is not a demo — the statistics, which are the hard part, are in it. Plus adds the things that cost us money to run.
Free
Everything you need to find out whether this works for you.
Free
- Unlimited habits
- Sleep, mood and journal
- The full Insights screen
- Data export whenever you want it
Plus
Most usefulFor when the numbers start telling you something.
$6/month
- Everything in Free
- AI coach and journal reflections
- Apple Health and Health Connect import
- Weekly and monthly written reports
- Priority support
Cancelling stops the billing and keeps your data. Deleting your account removes it — properly, including from our analytics — after a 30-day window in case you change your mind.
Questions
The things people actually ask
Is my journal used to train AI?
No. Journal text never leaves your account. The AI features send the statistics we computed — a correlation coefficient, a sample size — and the text of the specific entry you asked for a reflection on, and nothing is retained for training. It is also excluded from our own analytics: the event recorded when you write is a word count, not the words.
How is this different from a streak app?
A streak app rewards not breaking a chain. Crescendo measures whether the chain is doing anything. It correlates your habits against your sleep and mood, and only reports a relationship when it clears three thresholds at once: at least 20 paired days, a correlation of 0.25 or stronger, and a Bonferroni-corrected p-value of 0.00625 or lower.
What happens if it finds nothing?
It says so. The hypotheses are fixed in advance rather than searched for after the fact, so "nothing significant yet" is a real result the Insights screen is designed to show. An app that always finds a pattern is not measuring anything.
Do I lose my streak if I miss a day?
Usually not. A day counts towards a streak at 60% of its expected load rather than 100%, a habit due four days a week only contributes four sevenths of a day, and a today that is merely still in progress never breaks a run.
Can I get my data out?
Yes, in one click, as JSON — every habit, completion, journal entry, sleep record and mood log, plus your consent history. No support ticket, and no waiting period.
Does it work on my phone?
It is a web app that installs to your home screen and works on any modern browser. Native iOS and Android apps are in progress and will use the same API, so your data moves with you.
What do you do with my data?
We measure which pages and features help people, and whether our advertising reaches the right ones. That means page views, feature usage and conversions — never journal text, and never inferred health information sent to an advertising platform. You can decline all of it and the product works identically.
Give it a month and see what it finds
Twenty paired days is the minimum before the statistics will say anything at all. That is roughly three weeks of ordinary use.
Or leave an email and we'll tell you when the mobile apps land.