Now on the App Store

Understand the cycle.
Survive the week.

Tides is a cycle-tracking app for partners. Know what phase she's in, what to expect, and exactly what to do about it.

Download on the App Store

iOS 16 · Requires subscription · 7-day free trial

Menstruation
Follicular
Ovulation
Luteal
PMS
How it works

Five phases.
One app to navigate them all.

The menstrual cycle has five distinct phases, each with its own hormonal profile, energy level, and — critically — mood. Tides maps out exactly where she is and what that means in plain language.

Enter a period start date and the app does the rest, predicting upcoming phases and telling you what to expect at each one.

Days 1–5
Menstruation
The uterine lining sheds. Prostaglandins cause cramping. Energy is low. Be useful, be quiet.
Days 6–13
Follicular
Oestrogen rises. Energy and mood improve. The green light phase — make your plans now.
Days 14–15
Ovulation
LH surge, egg released. Peak energy, confidence, and mood. She is operating at maximum capacity.
Days 16–23
Luteal
Progesterone rises then falls. Energy dips. Mood becomes variable. Tread thoughtfully.
Days 24–28
PMS
Oestrogen and progesterone drop sharply. Serotonin follows. Stock up on chocolate and patience.
Features

Everything you need.
Nothing you don't.

👥
Multiple profiles
Track more than one person. Useful for partners, family members, or anyone whose cycle you want to understand.
📅
Cycle calendar
A colour-coded month view showing current and predicted phases at a glance. Future dates shown as predictions.
📝
Daily log
Record moods, flow intensity, and notes for any date. Tap a calendar day to jump straight to that entry.
🔔
What's coming
See when the next period, ovulation window, and PMS phase are due — with countdown dates so you can prepare.
📊
Adaptive cycle tracking
Predictions improve automatically as you log more periods, learning the actual average cycle length over time.
🔐
PIN lock
Protect the app with a 4-digit PIN. Recommended — this is sensitive data and not everyone's phone stays in their pocket.
🌙
Dark mode
Proper dark mode with adaptive phase colours designed to remain readable and recognisable against dark backgrounds.
📤
Data export
Export everything as JSON at any time. Your data, your device, your choice what to do with it.
Two tones

Choose your approach.

Tides has two content modes. Switch between them at any time in Settings.

Default
Informative & Supportive
Clear, straightforward information about each phase. What's happening hormonally, what to expect, and how to be helpful. No frills.
"Oestrogen rises during the follicular phase, improving energy and mood. A good time for plans, conversations, and being present."
Spicier Content
The Survival Guide
The same information, delivered with a tongue-in-cheek comedic spin. Frank, funny, and occasionally alarming. Relationships include "Spawn of Satan."
"Green light. Go, go, go. Book that dinner. Have that conversation. Enjoy it — Luteal phase is only two weeks away."
Privacy

Your data stays
on your device.

Tides stores everything locally using iOS device storage. There are no servers, no accounts, no cloud sync, and no analytics. We have no technical ability to see your data because we never receive it.

📱
On-device only
Storage
🚫
None
Data collected
👤
Not required
Account
🏥
Not used
HealthKit

Read the full Privacy Policy.

Pricing

Simple subscription.
Cancel anytime.

Both plans include a 7-day free trial. No payment taken until the trial ends. Subscriptions managed through your Apple ID — cancel any time from iOS Settings.

Monthly
£6.99 / month
7-day free trial
Auto-renews monthly. Cancel at any time.
Best value
Yearly
£29.99 / year
7-day free trial · Family Sharing
Includes Family Sharing. Auto-renews yearly. Cancel at any time.

Prices shown in GBP. Your local price may vary. Payment charged to Apple ID at confirmation of purchase. Read the full Terms of Use.