Comparison

Perfect OB Wheel vs EFM

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

Head to head
About

Perfect OB Wheel

This app is a comprehensive obstetrics calculator that provides detailed pregnancy information. It offers flexible input options and displays thorough results including estimated due dates, gestational ages, and fetal growth estimates.

Highlights
  • Flexible input (LMP, conception, EDC, ultrasound)
  • Fast data entry options
  • Detailed pregnancy results
  • Accurate date calculations
  • Persistence of last used data
  • Optional pregnancy tracking upgrade
Features
Currently charting
Read full description

Simple, fast, yet more thorough than any other pregnancy wheel available for the iPhone, Perfect OB Wheel is better than just a replacement for your trusty paper wheel. Here's why Perfect OB Wheel is your best choice of gestational calculator: 1) Input flexibility: Start with one of: • Last menstrual period (LMP) • Conception date • Estimated date of confinement/delivery (EDC) • Ultrasound dating: Number of weeks and days gestation as of a given date ("X Weeks"). 2) Input speed: Other wheels for the iPhone make you conform to them for entering your patient's information. Why not be able to choose based on how you are holding the phone and what else you are doing at the same time? • Use the numeric entry pad (0 3 3 0 2 0 0 8) and immediately see the results, OR • Spin the date wheel at the bottom of the screen and tap Next. 3) Thorough results: All the information you would expect from a classic wheel, plus more: • Estimated Due Date • LMP Date • Conception Date • 1st Trimester End Date • 2nd Trimester End Date • Gestational Age • Conceptional Age • Expected Fetal Length based on standard fetal growth curves • Expected Fetal Weight based on standard fetal growth curves ("How much does my baby weigh, doctor?") Results are relative to 'today' by default; this can be quickly changed to reflect any date by tapping the 'today' button and selecting a new date. 4) Accurate results: Perfect OB Wheel provides exact dates and accounts for all calendar variance, including leap years. 5) Persistence: Perfect OB Wheel remembers the date and date type you last used and restores them when launched to streamline your workflow. 6) Perfect OB Tracker upgrade: Available as an in-app purchase update, the Perfect OB Tracker lets you track any number of pregnancies, with at-a-glance due date and gestational age and one-tap access to all the data Perfect OB Wheel provides. A picture and text notes can be kept on each patient. Postpartum tracking is also available. Passcode locking is available for HIPAA compliance.

About

EFM

This is an instructional application for learning electronic fetal monitoring using a recognized algorithm and nomenclature. It is designed for educational purposes and is not a substitute for professional clinical judgment. Future updates aim to include data saving and demographic features.

Highlights
  • Electronic fetal monitoring instruction
  • NCHHD algorithm and nomenclature
  • Instructional purposes
  • Collaborative project inquiries
  • Future data saving capability
Features
Read full description

EFM is an electronic fetal monitoring instructional application utilizing the National Child Health and Human Development (NCHHD) algorithm and nomenclature. This application is intended for instructional purposes only and is not intended to be a replacement for clinical judgment. Evaluation of the effectiveness and acceptability of this application to learners is ongoing. If interested in possible collaborative projects utilizing this application please contact the developer. Future versions plan to include capability to save previous data and basic demographics and additional instructional materials.

Screenshots

Perfect OB Wheel4 screens
EFM4 screens

Verdict

The call

The clearest difference is review sentiment: Perfect OB Wheel at 83% against EFM's 0%. Perfect OB Wheel also leads on rating (4.9 vs 1.0) and update cadence (weekly vs every 12 months). EFM's advantage is price (Free vs $1.99) and in-app purchases (none vs 1). On 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

EFM is free to download; Perfect OB Wheel costs $1.99 up front. Perfect OB Wheel sells 1 one-off in-app purchase. EFM asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Perfect OB Wheel holds the better App Store score, 4.9 against 1.0. That said, the two scores are not equally well evidenced: Perfect OB Wheel has 3.6K ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 83% of Perfect OB Wheel's written reviews are positive against 0% of EFM's.

UpkeepUpdate frequency

Perfect OB Wheel ships an update weekly, EFM every 12 months. The most recent releases landed on November 6, 2026 and November 1, 2026 respectively.

Scorecard9 real differences · 2 level
Perfect OB Wheel versus EFM: the parameters behind the verdict, then further details
ParameterPerfect OB WheelEFM
Price$1.99Free — better
Rating4.9 (3.6K ratings) — better1.0 (3 ratings)
Positive reviews83.0% of reviews — better0.0% of reviews
Number of ratings3.6K — better3
Update frequencyWeekly — betterEvery 12 months
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
Best chart rank#21 — better—
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS13.07.0 — better
Further details — not scored
Size14 MB5 MB
Age rating17+12+
DeveloperEvan SchoenbergAugusta University

Customer experience

Perfect OB Wheel

All ratings3,578 ratings
Positive98.8%
Neutral0.5%
Negative0.7%
Written reviews200 reviews
Positive83.0%
Neutral6.5%
Negative10.5%

EFM

All ratings2 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews3 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Bugs and requests

Perfect OB Wheel

Reported bugs

3 issues
  • App crashes after update
  • Delivered today button not working after upgrade
  • Dates keep changing when entering info

Requested features

5 requests
  • Date-adjustment for women who have a five week menstrual cycle
  • More fields for infant info, apgars and weight
  • Ability to adjust cycle length
  • Ability to type in a gestation and get a date or type in a date and get a gestation
  • Calculate GA on a specific date

EFM

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Perfect OB Wheel

One-time1
  • Perfect OB Tracker$4.99
None

EFM

No in-app purchases

Questions

Is Perfect OB Wheel free?
Perfect OB Wheel costs $1.99, and also offers in-app purchases.
Is EFM free?
EFM is free to download, with no in-app purchases.
Which has better reviews, Perfect OB Wheel or EFM?
Perfect OB Wheel is rated higher. Perfect OB Wheel averages 4.9 out of 5 from 3.6K ratings, while EFM averages 1.0 from 3 ratings.
Do Perfect OB Wheel or EFM have ads?
Neither Perfect OB Wheel nor EFM shows ads.
Which is updated more often, Perfect OB Wheel or EFM?
Perfect OB Wheel ships an update weekly, and EFM every 12 months. Most recently, Perfect OB Wheel was updated on November 6, 2026 and EFM on November 1, 2026.

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