Comparison

FEMM Period Ovulation Tracker vs Chart35

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

FEMM Period Ovulation Tracker

This app helps women track their menstrual cycles, symptoms, and hormonal health. It offers detailed insights, charting tools, and access to a network of healthcare professionals for personalized care.

Highlights
  • Cycle and period tracking
  • Symptom tracking (physical and emotional)
  • Daily data input reminders
  • Cycle pattern charting
  • Medication tracking
  • Doctor-shareable charts
  • Hormone knowledge base
Features
Read full description

Are you looking to track your menstrual cycles and symptoms, get pregnant or avoid pregnancy? The FEMM app is more than just a period tracker: it provides you with cutting edge science that helps you keep track of your health, understand what is going on with your body, flag potential issues and connect with a network of doctors and nurses to provide you the best health care. We’re a new revolution in women’s health! Empower yourself and be an active player in your health care with our easy to use app! FEATURES * Easy data input to track your cycle or period. * Track physical and emotional symptoms to better diagnose potential health problems. * Daily reminder. Never forget to input your data through our app's notification feature. * View several Charts on a screen to help you understand your patterns. * Track medications you are currently taking. * Email and/or print your charts to share with your doctor, friends or family * Various view styles let you see and interpret your cycles better: calendar view, chart view and the detailed chart view, which let you see your symptoms. * Understand your health and the interplay of hormones in your body through our knowledge base. CONTACT OUR TEAM TO HELP YOU FIND: * a FEMM-trained doctor or FEMM health center near you * a FEMM teacher who can teach you how to chart and understand the interplay of hormones in your body

About

Chart35

This app helps users privately track their fertility observations using the Creighton Model FertilityCare System. It offers offline functionality, color-coded stamps, and various chart views. Users can securely share their data with practitioners.

Highlights
  • Creighton Model charting
  • Offline-first functionality
  • Color-coded observation stamps
  • Chart and calendar views
  • Peak day and post-peak tracking
  • Secure practitioner sharing
Features
Read full description

Chart35 is a private fertility-charting app for the Creighton Model FertilityCare System (CrMS). Record each day's observation, see your color-coded stamp and chart, and keep your record on your own device. YOUR DATA STAYS WITH YOU Chart35 is offline-first. Your observations live on your device and the app works with no connection. Account sync is optional. When you turn it on, your records are encrypted on your device before they are uploaded, so the server stores data it cannot read. CHART THE WAY YOU WERE TAUGHT - Color-coded stamps: red, green, white, and yellow, matching standard CrMS charting. - Observation codes for bleeding, mucus, and frequency, built from the codes you already use. - Peak Day and post-peak count tracking. - Chart and calendar views, with Normal, Compact, and Trend zoom to see one cycle or many at a glance. - Insights: cycle count, average cycle length, and a cycle-length trend at a glance. SHARE WITH YOUR PRACTITIONER Generate a read-only link to your chart for your FertilityCare Practitioner. The link is encrypted so the server cannot read the shared data, and you can revoke it at any time. BUILT FOR REVIEW Your notes stay private and are never included in a shared chart. You decide what syncs and what is shared. You can delete your account and data at any time. ABOUT THE METHOD Chart35 is a charting and record-keeping tool. It is not medical advice and does not interpret your fertility for you. The Creighton Model is learned with a certified FertilityCare Practitioner. Yellow-stamp (Base Infertile Pattern) use in particular should only follow a baseline established with your practitioner. To find a practitioner, see your instructor or a FertilityCare center. Chart35 is independent and is not affiliated with or endorsed by the Saint Paul VI Institute or the creators of the Creighton Model System. "Creighton Model" and "FertilityCare" refer to the method and are used to describe what the app charts.

Screenshots

FEMM Period Ovulation Tracker4 screens
Chart354 screens

Verdict

The call

The clearest difference is update cadence: Chart35 at every 6 days against FEMM Period Ovulation Tracker's every 4 months. Chart35 also leads on rating (5.0 vs 4.8) and device support (4 vs 2). FEMM Period Ovulation Tracker's advantage is ratings volume (4.1K vs 1). On price, ads, in-app purchases and monetization model there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Chart35 holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: FEMM Period Ovulation Tracker has 4.1K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

FEMM Period Ovulation Tracker ships an update every 4 months, Chart35 every 6 days. The most recent releases landed on November 1, 2026 and October 25, 2026 respectively.

Scorecard4 real differences · 6 level
FEMM Period Ovulation Tracker versus Chart35: the parameters behind the verdict, then further details
ParameterFEMM Period Ovulation TrackerChart35
PriceFreeFree
Rating4.8 (4.1K ratings)5.0 (1 ratings) — better
Positive reviews65.0% of reviews—
Number of ratings4.1K — better1
Update frequencyEvery 4 monthsEvery 6 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad, iPod, Apple Watch — better
Requires iOS15.015.0
Further details — not scored
Size27 MB5 MB
Age rating4+4+
DeveloperFEMM FoundationStephens Page LLC

Bugs and requests

FEMM Period Ovulation Tracker

Reported bugs

4 issues
  • App crashes on opening after iOS updates
  • Date/cycle tracking gets mixed up or stuck
  • Symptom/observation data not saving properly
  • Analysis/charting features not functioning as expected

Requested features

6 requests
  • Add option to track seminal fluid observations
  • Integrate with Apple Health for seamless data sync
  • Expand mood/emotion tracking options
  • Improve date/cycle navigation and data entry
  • Provide better postpartum/breastfeeding support
Show 1 more
  • Offer calendar view in addition to chart view

Chart35

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

FEMM Period Ovulation Tracker

No in-app purchases

None

Chart35

No in-app purchases

Questions

Is FEMM Period Ovulation Tracker free?
FEMM Period Ovulation Tracker is free to download, with no in-app purchases.
Is Chart35 free?
Chart35 is free to download, with no in-app purchases.
Which has better reviews, FEMM Period Ovulation Tracker or Chart35?
Chart35 is rated higher. FEMM Period Ovulation Tracker averages 4.8 out of 5 from 4.1K ratings, while Chart35 averages 5.0 from 1 ratings.
Do FEMM Period Ovulation Tracker or Chart35 have ads?
Neither FEMM Period Ovulation Tracker nor Chart35 shows ads.
Which is updated more often, FEMM Period Ovulation Tracker or Chart35?
FEMM Period Ovulation Tracker ships an update every 4 months, and Chart35 every 6 days. Most recently, FEMM Period Ovulation Tracker was updated on November 1, 2026 and Chart35 on October 25, 2026.

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