Privacy-first cycle tracking

Your body.
Your data.
Full stop.

Ferne is a cycle tracker built on one principle: your health data belongs to you — and only you. Everything stored on your device. No account required. No cloud. No selling your data to anyone.

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March 2025
Day 14 of 28
🔒 On-device
Period
Fertile
Today
Avg cycle
28d
Next period
14d
📱
100% on-device storage Your data never leaves your phone. Not a policy — a technical fact.
🚫
No account required Start tracking immediately. We don't know who you are.
💰
Privacy-first pricing Privacy-first shouldn't mean premium-priced. Full features at $3.99/mo.
📤
Your data, exportable One tap to download everything as CSV or PDF. Always.
Why Ferne

Tracking that actually respects you.

Most cycle apps treat your health data as a business asset. They store it, analyse it, and find ways to make money from it. Ferne is built on a different assumption entirely: that your body data belongs to you, and only you.

Everything else follows from that.

What Ferne does differently
✓ All data stored on your device — technically impossible to share
✓ No account required. We don't know who you are.
✓ Free tier includes everything except encrypted sync
✓ ADHD-friendly reminders, no noise, no pregnancy push
✓ Premium at $3.99/mo — because privacy shouldn't cost more
What's included

Everything you need.
Nothing you don't.

01
Cycle Tracking
Log your cycle with one tap. All data stored locally on your device. No account, no cloud, no exceptions.
02
Symptom & Mood Logging
Track how you feel across your cycle. Ferne identifies patterns over time and surfaces them clearly — without lecturing you.
03
ADHD-Friendly Reminders
Customisable reminders that work the way your brain does. Gentle nudges, not chaos. You're in control of when and how.
04
One-Tap Data Export
Download all your data as CSV or PDF in one tap. Share with your doctor, keep for yourself, or delete it entirely. Always.
05
Encrypted Sync (Premium)
Use Ferne on multiple devices with optional end-to-end encrypted sync. Only you hold the key. Even we can't read it.
06
No Pregnancy Framing
Ferne is a cycle tracker, not a fertility app. No assumptions about what you're tracking for. It's your cycle, your reasons.
"We built Ferne so that privacy isn't a feature you pay for — it's the foundation everything else sits on."
🏠
Local-first architecture Your data is processed and stored entirely on your device. There's no server that holds your health information because there's no server that receives it.
🔑
End-to-end encryption for sync If you choose to sync across devices, your data is encrypted before it leaves your phone. The key never leaves your device.
💸
We make money from subscriptions, not data Our business model is simple: you pay us a fair price, we give you great software. That's it. We have no incentive to monetise your health data.
Pricing

Simple, honest pricing.

Two tiers. No dark patterns, no surprise charges. The free tier is genuinely useful — we're not going to pester you to upgrade.

Free
$0
forever
✓ Cycle tracking
✓ Symptom & mood logging
✓ Pattern insights
✓ ADHD-friendly reminders
✓ One-tap data export
—  Encrypted multi-device sync
✦  Founding Member
Premium
$3.99
per month · or $29.99/year
✓ Everything in Free
✓ End-to-end encrypted sync
✓ Use across all your devices
✓ Priority support
✓ Early access to new features
Early access

Be first in.
Before we launch.

Join the waitlist and you'll hear from us first — before anyone else. Founding members will get priority access and a locked-in price.

✓  You're on the list. We'll be in touch before launch.

No spam, ever. Unsubscribe any time.