Ebb: Period & Cycle Tracker

A cycle tracker that tells you the truth, including how sure it is. Built for irregular and PCOS cycles, Ebb embraces uncertainty instead of hiding it. Private by default, it helps you understand your cycle with realistic expectations while keeping your data under your control.

Ebb is a period and cycle tracker that's honest about uncertainty. Instead of showing a single predicted date that pretends to be certain, Ebb presents a clear prediction window together with how confident it actually is. Every prediction explains the reasoning behind it in plain language, so you know what the app knows and what it doesn't. Whether your cycles are regular or unpredictable, you can plan with realistic expectations instead of false precision.

WHY EBB IS DIFFERENT

Honest predictions

Every forecast includes a real confidence level and the reasoning behind it in plain language. When your cycles are regular, the prediction window narrows naturally. When they vary, it widens instead of pretending to know more than the available data allows. Ebb reflects uncertainty honestly rather than hiding it.

Built for real, irregular cycles

Long cycles, short cycles, PCOS, or cycles that simply don't run like clockwork—Ebb is designed for real-world variability. Instead of treating irregularity as an error, it shows your normal range as a prediction band based on your own history. Your body isn't expected to fit a perfect schedule, and Ebb never shames you for being unpredictable.

Log your period, day by day

One tap marks today. Ebb tracks how many days your period actually lasts based on what you enter and never invents days you didn't log. While you're bleeding, it gently reminds you to keep tracking, then stops once your period ends.

Your whole cycle, at a glance

A calm two-month calendar shows your logged period days, the day each period started, and the predicted window ahead. Everything is organized so you can quickly understand both your cycle history and upcoming predictions.

Insights, never a diagnosis

See patterns in your own data, including cycle-length trends, period length, and which symptoms cluster during each phase of your cycle. Everything is computed directly on your phone. Ebb provides observations to help you understand your patterns, never medical claims or diagnoses.

PRIVATE BY DEFAULT

Your data lives on your phone. iCloud backup is opt-in, and Ebb never tells you your data is backed up when it isn't. Apple Health sync is optional and fully under your control. No ads, no tracking, and your data is never sold.

EBB PREMIUM (optional)

Upgrade for deeper analysis with symptom forecasts for your next cycle, a regularity trend, complete symptom-by-phase patterns, and a doctor-prep report you can share with a clinician. A 7-day free trial is included. Subscriptions renew automatically until cancelled, and you can cancel anytime in your App Store settings.

Predictions, logging, the calendar, and backup are always free.

Terms of Use: [https://docs.google.com/document/d/e/2PACX-1vRu6ERK8wX9vx_dPLtm66YRyLNSU9j3kTQtoGJ5GB-nO2VuN42il50YV9v_Njh3cUzJeU-6ZZYudIh1/pub](https://docs.google.com/document/d/e/2PACX-1vRu6ERK8wX9vx_dPLtm66YRyLNSU9j3kTQtoGJ5GB-nO2VuN42il50YV9v_Njh3cUzJeU-6ZZYudIh1/pub)

Privacy Policy: [https://docs.google.com/document/d/e/2PACX-1vSWGWjnPcHXF0JFJnCyRszDYMZa_GoqnfgTAFPCsdrI371XMS7p44olhGmc7-rCcftxGUVP_zJl0I-h/pub](https://docs.google.com/document/d/e/2PACX-1vSWGWjnPcHXF0JFJnCyRszDYMZa_GoqnfgTAFPCsdrI371XMS7p44olhGmc7-rCcftxGUVP_zJl0I-h/pub)