Cadence Cycle Tracker

Cadence predicts your period, then tells you how wrong it was. Every prediction it makes is recorded and later scored against what actually happened. That error history feeds back into the next forecast as a bias correction, and you can inspect the accuracy record yourself whenever you like. Everything stays on your iPhone. No account, no sign-in, no servers, no analytics. Cadence makes no network requests of any kind, and its database is encrypted with iOS file protection. You can optionally sync flow and test results with Apple Health, or leave that off and keep it entirely local. WHAT YOU GET • A cycle ring showing where you are today and which phase you're in • A predicted window with an honest confidence level: high, medium or low, based on how variable your cycles actually are • An accuracy record showing how close each past prediction landed • Fast daily logging: flow, how you feel, and what your body is doing • Optional LH test logging, which confirms ovulation rather than estimating it • A month calendar marking logged, predicted and fertile days • A one-page PDF summary for a doctor's appointment, generated on device • Face ID or passcode lock HONEST ABOUT UNCERTAINTY A new user sees “medium” confidence rather than a precise-looking date, because a handful of cycles is not enough data to claim precision. Predicted and fertile days are labelled as estimates, and only a logged LH test marks an ovulation as confirmed. Cadence is built not to present a guess as a fact. Cadence is a tracking tool. It is not a contraceptive or a medical device, and it does not diagnose anything.