Privacy-first cycle tracking

Your body.
Your data.
Full stop.

Ferne tracks your cycle without an account, without storing anything on our servers, and without pregnancy obsession. We don't ask you to trust us with your data. We make it so that you don't have to.

✓  You're in. We'll send the occasional update — no spam, ever.

No spam, ever. Unsubscribe any time.

March 2025
Day 14 of 28
🔒 On-device
Period
Fertile
Today
Avg cycle
28d
Next period
14d
Your data never leaves your phone Not a policy promise. There's no server that receives it — because we never built one.
No account required We don't want your data. We don't need your email to let you use your own health tracker.
Privacy-first pricing Half the price of Flo. No ads, no data sales. Just software you pay for fairly.
Import your existing data Moving from another app? Bring your history with you. One tap import, nothing lost.
Why Ferne

Just tracks your cycle.
That's it.

Every other cycle app is trying to get pregnant — or at least assumes you are. They're built around fertility windows, ovulation predictions, and TTC communities. And somewhere along the way, they decided your health data was a business asset too.

Ferne is for women who just want to know when their period is coming, understand their patterns, and not be surveilled while doing it.

"We don't want your data. We built Ferne so there's no server to breach, no account to hack, and nothing to sell."
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 encrypted backup If you choose to back up your data, it's encrypted before it leaves your phone. The key stays on your device — stored in your own iCloud or Google Drive, not ours.
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 upsell pressure, no features taken hostage. Free does what it says. Premium earns its price.

Free
$0
forever · no account required
Cycle tracking and period prediction
Symptom and mood logging
Temperature / BBT logging
Cycle phase indicator
ADHD-friendly mode
One-tap quick log from notifications
Home screen widget
Configurable reminders
Import data from other apps
CSV export — your data, always
Works fully offline
From the blog

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