Launching, Web, Android
Petal
Cycle tracking with no account, no cloud and no compromise.
Petal is a period and cycle tracker designed around privacy. All data remains on the user's phone or in their browser. It provides predictions, symptom insights and a report suitable for a medical appointment, and it is completely free.
Your cycle is your business.
Nothing is transmitted or stored on a server.
Predictions and symptom patterns over time.
A clear report to share at appointments.
What Petal does.
A period and cycle tracker that never sends your data anywhere. No account, no cloud: everything stays on your phone or in your browser. Predictions, symptom insights and a report for your doctor, completely free.
Predictions that learn
Next period, fertile window and ovulation estimate from your own last six cycles, with an honest irregularity warning.
Patterns you can see
Flow, symptoms, mood and temperature in a couple of taps, and when symptoms usually appear.
Ready for the doctor
A one-page summary you can print or save as a PDF, plus a spreadsheet export.
Private by construction
The Android app has no internet permission at all; the web app's security policy blocks every connection.
Privacy. No account and no server storage. All data remains on the device.
At a glance.
Designed for
Anyone who tracks their cycle and wants that data to stay theirs.
Pricing
Free. No ads, no tracking.
Available on
Web, Android
Built on the layer
- On-device onlyNo server storage at all. Data never leaves the phone or browser.
- NexusLayer CloudContainerised services on NexusLayer servers in Germany, behind TLS, with nightly backups.
Let's build it together.
Whether you want to run your own agents on the layer, discuss one of our products, or need a partner for an AI, Java or enterprise project, we respond within one working day.