Perfect OB Wheel vs EFM
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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.
- 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
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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.
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.
- Electronic fetal monitoring instruction
- NCHHD algorithm and nomenclature
- Instructional purposes
- Collaborative project inquiries
- Future data saving capability
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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
Verdict
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
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.
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.
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.
| Parameter | Perfect OB Wheel | EFM |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 4.9 (3.6K ratings) — better | 1.0 (3 ratings) |
| Positive reviews | 83.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 3.6K — better | 3 |
| Update frequency | Weekly — better | Every 12 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Best chart rank | #21 — better | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 13.0 | 7.0 — better |
| Further details — not scored | ||
| Size | 14 MB | 5 MB |
| Age rating | 17+ | 12+ |
| Developer | Evan Schoenberg | Augusta University |
Customer experience
Perfect OB Wheel
EFM
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
Perfect OB Wheel
- Perfect OB Tracker$4.99
EFM
No in-app purchases
Questions
Is Perfect OB Wheel free?
Is EFM free?
Which has better reviews, Perfect OB Wheel or EFM?
Do Perfect OB Wheel or EFM have ads?
Which is updated more often, Perfect OB Wheel or EFM?
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