Forecast: Cycle Syncing

A period tracker that looks like a weather app. Honest windows instead of fake exact dates, and everything stays on your phone.

Someone glances at your phone and sees a storm front rolling in. To them it's the weather. To you it's the week before your period.

Forecast is a period and cycle tracker built inside a real weather app. The sky shows where you are in your cycle. Rain is your period. Clearing skies are the follicular days. A bright sky is ovulation. It clouds over through the luteal phase, and a storm builds in the days before your period. There's a seven-day outlook and a month calendar underneath, like any weather app. Tap once and the real dates are there.

Most apps name a single exact day your period will arrive. Then it doesn't come, and you lose three days sure that something is wrong. Forecast anchors ovulation to about 13 days before your next period, then hands you a window and marks it "estimated" until your own logs tighten it. It learns from your last three cycles, and the more you log, the smaller the window gets. When a forecast lands inside its window, the app tells you, so you watch it get things right before you trust it.

Log your morning temperature and Forecast confirms ovulation from the rise in your readings, after it happens, the way the symptothermal method works.

Your data never leaves your phone. No account, no sign-in, no cloud, no trackers. Because it looks like weather, you can open it on the train or hand it to a friend and nothing shows.

The sky is drawn live. Clouds drift, the light moves across the day, rain falls, stars come out.

Forecast is not a contraceptive or a medical device.