iOS app · live · 4.9★
Iris
A complete cycle-tracking suite built on a refusal. No subscription, no locked features, and no health data leaving the phone. The category leaders charge $60 a year and share data with third parties. Iris charges nothing and can't share what it never collects.
- Platform
- iPhone, iPad, Mac, Vision · App Store
- Rating
- 4.9★ worldwide · 1,000+ downloads
- Languages
- 12, from Japanese to Polish, 820 localized strings each
- Model
- Free forever · optional $2.99 one-time to remove ads
- Data
- On device; optional sync to the user's own iCloud. No servers, no accounts, no analytics SDKs
- Stack
- SwiftUI · Swift Charts · HealthKit · CloudKit · StoreKit 2 · ~57K lines, 98 test files
Engineering notes
The prediction engine goes past calendar math. It learns each user's luteal-phase length, shifts ovulation estimates when an LH test is logged, and confirms ovulation from basal body temperature with a proper coverline and three-reading thermal shift. That is the symptothermal method, implemented honestly. There is a PCOS-friendly irregular mode that gives ranges instead of false-confidence dates, and contraceptive and postpartum modes that change the whole model rather than hiding a few buttons.
The rest of the suite is included, not upsold. A colour-coded calendar and fertile window, ovulation and PMS phases, fourteen symptoms plus mood, discharge, sleep and weight logging, BBT charts, pill and hydration reminders, postpartum milestones, two-way Apple Health sync, partner sharing, PDF health reports for a doctor, and twelve languages. Every one of those is free.
Partner sharing publishes a read-only snapshot through CloudKit, with no account and no server of mine in the middle. Reports render to PDF for doctors. Every feature works offline.
Growth, also automated
Iris markets itself. A content pipeline generates infographic posters with an image model, gates every one against a written creative contract (word caps, mobile-safe geometry, a diversity ledger so no two posts repeat a topic or a look), and publishes them as Instagram Reels, Stories, and Pinterest pins on a daily schedule. The App Store listing runs localized ASO: screenshots and metadata in eleven languages, produced by another pipeline. One person ships the whole stack: product, engineering, distribution. The full write-up is at the Iris growth pipeline.