Know your body.
Keep it between you and the moon.
Ondelle is a private period and ovulation tracker with cycle estimates, reminders, and gentle insights. Your health entries stay on your device unless you choose to export them. Optional Premium adds advanced patterns, charts, reports, and pregnancy details.
Available on iPhone and iPad · Free to download · Optional in-app purchases
Our promise: your health entries live on your device unless you choose to export them. No account is required. Apple and RevenueCat process purchase information to verify Premium access.
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
Estimated ovulation and fertile-window timing can help you understand your cycle. Estimates do not confirm ovulation and must not be used as contraception.
Daily guidance
Gentle educational guidance and comfort ideas help you notice changes over time.
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.
- Health entries are stored on your device unless you export them
- No account or email required to use the app
- Your health data is never used for advertising
- Delete everything, any time, in one tap
Your entries.
Your device.
Apple and RevenueCat process purchase information to verify Premium. Your health entries are not used for advertising.