Where you are, today
Cycle day, current phase, and what tends to come next. A colour-coded calendar with fertile-window and ovulation estimates.
Private beta · iPhone · Autumn 2026
Fase reads your cycle phase, sleep, food and training into one readiness score — and shows you where it’s heading, so you can plan around your actual capacity instead of guessing at it.
No account. No email required to use the app. Nothing sold, ever.
Your energy, mood and capacity follow a rhythm.
Phase, sleep, food and training become one number.
Not just today — where it’s likely heading.
Plan the hard week for when you have it in you.
Readiness
Whoop and Oura were built to answer an athlete’s question. Yours is bigger — the workout, yes, but also the meeting, the conversation, the day that is going to ask a lot of you.
Fase reads the one input those devices cannot see: where you are in your cycle. Combined with your sleep, what you have eaten and how you have trained, it gives you a single honest number for how much you actually have.
And because your cycle is the one thing about tomorrow that is genuinely forecastable, Fase can show you the days ahead — as estimates, with the uncertainty visible.
Readiness · next 14 daysEstimated
Recorded Estimated Likely range
Illustrative. Estimates are based on your own logged history and can be wrong.
What it does
Cycle day, current phase, and what tends to come next. A colour-coded calendar with fertile-window and ovulation estimates.
Trends across months for mood, energy, sleep and symptoms. What tends to happen to you, and roughly when.
Meals, movement and supplement information organised by phase. Suggestions and context — never instructions, never promises.
Nora
Illustrative conversation. Nora is not a medical professional.
Nora is the assistant inside Fase. She has read what you’ve logged — your phase, last night’s sleep, that pattern from three cycles ago — so you never start from scratch.
Ask about a symptom, a stretch of bad days, or an entry you made weeks ago. The answer comes from your data, not from a general article about cycles.
She isn’t a doctor and won’t pretend to be one. For anything that matters, talk to a healthcare provider.
Trying to conceive
If you’re tracking to conceive, Fase estimates ovulation from what you actually measure — basal body temperature, LH tests, cervical mucus — rather than assuming your cycle matches an average. There’s a pregnancy mode for when you need it.
Your own temperature and LH readings adjust the estimate, instead of a calendar prediction standing in for your body.
Fertile-window and ovulation estimates are shown as estimates, with their uncertainty visible. We don’t dress a guess up as a certainty.
Fase gives you a clearer read of your own body. It doesn’t claim to improve your chances, and it must not be used as contraception.
Fase is not fertility treatment and not a substitute for medical care. If you’ve been trying to conceive for twelve months — or six if you’re 35 or older — or you have any concern about your fertility, please talk to a healthcare provider.
Privacy
Where cycle and fertility data lives is a fair thing to worry about. So Fase is built to hold as little as it can and still be useful to you.
Open the app and start — there’s no sign-up screen. Your history is held under a random device ID, not your name or your email address.
We don’t sell your data, we don’t run ad networks inside the app, and we never use reproductive health data for advertising.
Partner mode shares only what you choose, with who you choose — and shows you a log of every time it’s opened. Switch it off whenever.
Read the full Privacy Policy.
Private beta
We’re opening a small beta on iPhone this autumn. Leave an email and we’ll tell you when there’s a spot — that address is used for this and nothing else.
iPhone · United States · Autumn 2026