Every feature free. No subscription. No data sharing. Ever.
Most period apps charge $10-15/month and have been caught sharing your reproductive health data with advertisers. Iris keeps everything on your device — no server, no account, no telemetry. Your cycle data never leaves your phone.
PERIOD & CYCLE TRACKING
Log your period and Iris predicts your next one, fertile window, ovulation day, and PMS phase — all mapped out weeks in advance. Colour-coded calendar, day log, and smart reminders included.
IRREGULAR CYCLE TRACKING
Iris detects cycle variability from your data and switches to honest prediction ranges instead of single dates. No fertile window guessing for irregular users. Built for PCOS, perimenopause, and anyone whose body doesn't fit the textbook.
PERSONAL INSIGHTS & PATTERN DETECTION
Iris turns your daily logs into useful patterns. See which symptoms, moods, discharge types, activity and vitals appear most often in each cycle phase, then tap into any pattern for phase distribution, cycle-day timing, recent history and prediction notes.
After enough history, Iris can help you spot recurring signals like fatigue, cramps, mood shifts or discharge changes before they appear — with insights calculated privately on your device.
LH STRIP LOGGING
Log your daily ovulation test result — Negative, Positive, or Peak. Iris immediately shifts your ovulation estimate to reflect your actual LH surge. Over time, Iris learns your personal luteal phase length and uses it to sharpen every future prediction — replacing the generic 14-day default with your actual biology. No other free app does this.
BBT TRACKING
Log your basal body temperature each morning and Iris calculates your personal coverline. When three consecutive readings rise above it, Iris marks a confirmed thermal shift — retrospective confirmation that ovulation occurred. Pair BBT with LH strips for the Symptothermal Method: the most accurate natural fertility awareness method, completely free.
APPLE HEALTH SYNC
Bidirectional sync with Apple Health. Iris reads your period history, BBT from connected thermometers, sleep, and weight. Period days, BBT, LH results, and cervical mucus data are written back to your Health dashboard. Iris data always wins — Apple Health only fills fields you haven't already logged.
CONTRACEPTIVE & POSTPARTUM MODE
On the pill, hormonal IUD, or copper IUD? Contraceptive Mode pauses ovulation predictions, labels bleeds as withdrawal bleeds, and adds a daily pill reminder. Just had a baby? Postpartum Mode pauses predictions while you recover, then resumes when you're ready.
SYMPTOM & MOOD TRACKING
Log mood, 14 symptoms (cramps, bloating, fatigue, acne, brain fog, hair shedding, and more), discharge type with fertility context, sleep, weight, and notes for any day.
HORMONE EDUCATION
Visualise estrogen, progesterone, FSH, and LH across your full cycle — mapped to your specific cycle length so the chart reflects your actual rhythm.
PRIVATE BY DESIGN
Your data stays on your iPhone. No servers. Optional iCloud sync goes to your own iCloud account — we never see it. No telemetry. No data-collection SDKs.
100% FREE — NO EXCEPTIONS
No premium tier. No subscriptions. No paywalls. Every single feature — LH logging, BBT charting, irregular cycle detection, Apple Health sync, contraceptive mode, postpartum mode, and more — is completely free for everyone, forever.
Download Iris. Your cycle is yours.
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