Monthly
$2.99 USD / month
14 days free, then renews monthly until canceled.
Creighton Model FertilityCare · CrMS
Chart the Creighton Model, on every device.
Chart35 turns your daily observations into a clear CrMS chart - peak day, cycle length, and stamps - with optional encrypted sync across your devices.
⌚ Also on Apple Watch, paired with the iPhone app.
Opening the Mac or Windows download
- macOS: right-click Chart35 in Applications and choose Open, then Open again. If it says the app is “damaged,” run
xattr -dr com.apple.quarantine /Applications/Chart35.apponce in Terminal, then open it. - Windows: on the “Windows protected your PC” screen, click More info, then Run anyway.
Bleeding
Dry / infertile
Fertile
Yellow stamp
Everything you chart, nothing you don't
Built around the Creighton Model as it's actually taught - the stamps, the peak day, and the rules you learn from your FertilityCare Practitioner.
🗓️
Daily observations
Record bleeding, mucus, and the CrMS observation codes as you go. Chart35 builds the standard stamp for each day automatically.
⭐
Peak day & cycle analysis
Your peak day, post-peak count, and cycle length are calculated for you, with a trend view across cycles.
🔒
End-to-end encrypted sync
Optional Chart35 Sync encrypts your chart on your device before it ever leaves it. We can't read your data - only you can.
🩺
Share with your practitioner
Send a read-only link to your FertilityCare Practitioner or doctor. No account needed on their end.
⌚
Phone, watch & web
Log an observation from your Apple Watch, review on your phone, and print from the web. Chart35 Sync keeps supported devices current.
📶
Works offline
It's a full offline-first app. Chart on a plane or in a basement clinic; optional Chart35 Sync catches up when you're back online.
Optional encrypted sync, priced simply
Local charting, export, and deletion remain free. Subscribe only if you want encrypted cloud backup and multi-device continuity.
Annual
$24.99 USD / year
14 days free, then renews annually until canceled.
See Chart35 Sync plans
Available to U.S. customers on the web. Applicable sales tax is added at Checkout. Cancel anytime from Settings → Chart35 Sync before renewal. Purchasing inside the iPhone and Android apps is not currently available.
Your fertility data stays yours
Chart35 encrypts your observations end-to-end. The chart, the codes, the notes - all of it is unreadable on our servers. Export it as JSON or CSV anytime, and delete your account and cloud data whenever you want.
How it works
The same routine you already follow, made faster.
Observe
Make your observations through the day, the Creighton way.
Record
Tap in the day's most fertile sign and any notes. Chart35 assigns the stamp.
Review
Watch your peak day and cycle take shape, with insights across cycles.
Share
Send a read-only chart to your practitioner when you follow up.
Start your chart today
⌚ Also on Apple Watch, paired with the iPhone app.
Opening the Mac or Windows download
- macOS: right-click Chart35 in Applications and choose Open, then Open again. If it says the app is “damaged,” run
xattr -dr com.apple.quarantine /Applications/Chart35.apponce in Terminal, then open it. - Windows: on the “Windows protected your PC” screen, click More info, then Run anyway.
About the method. The Creighton Model FertilityCare System (CrMS) and NaProTECHNOLOGY were developed at the Saint Paul VI Institute. Chart35 is an independent app for keeping your own chart; it is not affiliated with, endorsed by, or a substitute for the Saint Paul VI Institute, Creighton University, or FertilityCare Centers of America. Chart35 helps you record and review your observations - it does not teach the method or interpret your chart for you. To learn the system and its rules, work with a trained FertilityCare Practitioner.