Arythm: Couples Period Tracker

Arythm syncs her period and cycle to your phone — encrypted, partner-only. Free for 7 days. Works with Oura, Apple Health, or just her own logging.

She's tired of explaining her cycle. You're tired of guessing. Same problem.

Arythm syncs the current phase of her cycle to your phone — encrypted, partner-only. You see where she is and how to actually help, so she's supported without the emotional labor of explaining it again. Free for 7 days.

HOW IT WORKS • She connects Apple Health or Oura — or just logs her period right in Arythm • Her current cycle phase is encrypted on her device, end-to-end • Only you see it — never the cloud, never us, never anyone else • Send a quick voice memo or a nudge when she needs you • You both get tips, body info, and a read on her energy

NO RING REQUIRED • A simple shared calendar — she taps to log her period, that's it • Arythm predicts her phase from her history, even with no wearable at all • Already on Oura or Apple Health? It folds that in automatically • One calendar, however she tracks — logged days and predicted days, clearly shown

BUILT FOR THE DAYS YOU CAN'T READ HER • No more "I'm fine" when she's not fine • You stop guessing why she's tired today • She stops having to translate her body into your language • You actually become helpful instead of confused • Built for the days she needs you to just know

WHAT YOU SEE AS A PARTNER • Her current cycle phase, updated automatically • A calendar of where she's been and what's coming • Tips for how to actually be supportive this week • A read on her energy and rest — never raw numbers • How long the current phase will last

PRIVACY IS THE PRODUCT • End-to-end encrypted (AES-256-GCM, Curve25519 key exchange) • No raw health data leaves her device • The server only ever sees an unreadable blob — never your actual cycle data • When you unlink, all shared data is deleted immediately • No ads, no data sales, no third-party tracking

YOUR RING ALREADY KNOWS • Best with Oura — temperature-based phase detection, no daily logging needed • Works with Apple Watch cycle tracking too, through Apple Health • Already use Flo, Clue, or Apple Health? Arythm reads from those automatically • No wearable? Her own logging works just as well — nothing's gated behind a ring

PREMIUM • Free for 7 days — see the whole thing before you pay a cent • Then $3.99/mo or $24/yr — two bucks a month if you go yearly • Partner pays, sharer has free access • Cancel anytime

She doesn't have to explain. You don't have to guess. Arythm is the quiet, private way two people stay in sync.

TERMS Auto-renewable subscription — $24/year or $3.99/month. Payment is charged to your Apple ID at purchase confirmation. It renews automatically unless canceled at least 24 hours before the current period ends; manage or cancel anytime in your App Store account settings. Terms of Use (EULA): https://arythm.app/terms Privacy Policy: https://arythm.app/privacy