Know your body.
Keep it between you and the moon.
Ondelle is a calm, beautiful period & ovulation tracker. Predictions, daily guidance, and gentle insights — with every entry stored on your phone, never on a server.
Launching 2026 · Free to download
Our promise: your cycle data lives on your device. No account required, no cloud copies, nothing sold or shared — ever.
What Ondelle does
Gentle tracking, real insight
Cycle predictions
A beautiful moon dial shows where you are today, when your next period is likely, and how your unique rhythm flows.
Fertile window
Ovulation estimates and a clear fertile window — whether you're trying to conceive or just want fewer surprises.
Daily guidance
What's happening in your body each day, with comfort tips and foods that help with cramps, bloating, and low-energy days.
Effortless logging
Flow, symptoms, and moods in a tap or two. Patterns emerge over time — Ondelle learns your normal.
Every stage
Modes for tracking, trying to conceive, and pregnancy — Ondelle meets you where you are.
Locked & discreet
An optional passcode keeps Ondelle for your eyes only, with backups you control.
Private by design
Your body's data belongs to you
Most period apps send your most personal information to their servers. Ondelle was built the opposite way — on purpose.
- Everything you log is stored on your own phone
- No account or email required to use the app
- Your health data is never used for advertising
- Delete everything, any time, in one tap
"Nothing leaves
your phone."
It's not a feature toggle or a promise buried in settings. It's how Ondelle is built.