Comparison

NFP Charting vs Chart35

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

Head to head
About

NFP Charting

Track your Natural Family Planning (NFP) charts online using the Billings Ovulation Method. This app allows you to enter data, share charts with your teacher, and view current and previous cycles. It is designed for users already trained in the Billings Ovulation Method.

Highlights
  • Track NFP charting data online
  • Share charts with teachers
  • Email charts
  • View current and previous cycles
  • Leave notes for teachers
  • Access from computer
Features
Read full description

Allows one free month of NFP Charting. The NFP Charting application allows you to keep track of your NFP chart online. (Note: This app is meant to be used with the Billings Ovulation Method of NFP Charting. There is no support for the Sympto-Thermal method.) This utility is not designed to teach you proper use of the Billings Ovulation Method of Natural Family Planning. It will not be useful to you unless you have been trained by a WOOMB certified teacher. You can find the nearest WOOMB certified teacher at http://www.boma-usa.com (for the United States) or http://www.WOOMB.org worldwide. FEATURES: -Enter your NFP Charting data from anywhere -Share your chart with your teacher -Email your chart to anyone -View your current cycle as well as your previous one -Leave notes for your teacher -Access your cycle from a computer at http://www.nfpcharting.com

About

Chart35

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

NFP Charting4 screens
Chart354 screens

Verdict

The call

The clearest difference is in-app purchases: Chart35 at none against NFP Charting's 6. Chart35 also leads on update cadence (every 6 days vs every 4 months). NFP Charting's advantage is iOS requirement (12.0 vs 15.0). On price, ads and device support 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. NFP Charting sells 6 one-off in-app purchases. Chart35 asks for nothing beyond the download.

UpkeepUpdate frequency

NFP Charting ships an update every 4 months, Chart35 every 6 days. The most recent releases landed on June 11, 2026 and September 19, 2026 respectively.

Scorecard3 real differences · 7 level
NFP Charting versus Chart35: the parameters behind the verdict, then further details
ParameterNFP ChartingChart35
PriceFreeFree
Rating4.3 (6 ratings) — better—
Positive reviews49.3% of reviews—
Number of ratings6 — better—
Update frequencyEvery 4 monthsEvery 6 days — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod, Apple Watch — better
Requires iOS12.0 — better15.0
Further details — not scored
Size6 MB5 MB
Age rating4+4+
DeveloperLawson CulverStephens Page LLC

In-app purchases

6 purchases

NFP Charting

One-time6
  • One Month Account Extension$2.99
  • One Month$2.99
  • Six Months Account Extension$11.99
Show 3 more
  • Six Months$14.99
  • One Year Account Extension$19.99
  • One Year$24.99
None

Chart35

No in-app purchases

Questions

Is NFP Charting free?
NFP Charting is free to download, with in-app purchases available.
Is Chart35 free?
Chart35 is free to download, with no in-app purchases.
Do NFP Charting or Chart35 have ads?
Neither NFP Charting nor Chart35 shows ads.
Which is updated more often, NFP Charting or Chart35?
NFP Charting ships an update every 4 months, and Chart35 every 6 days. Most recently, NFP Charting was updated on June 11, 2026 and Chart35 on September 19, 2026.

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