Comparison

PRN Graph vs ORReady

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

Head to head
About

PRN Graph

Features
Read full description

The Perined-Hoftiezer birth weight curves show the optimal birth weight (and its distribution) of children born at the corresponding gestational age. The curves are differentiated by gender. Identifying small children is important for reducing mortality and morbidity. These curves are based on data from the perinatal registration of newborns in the Netherlands. The curves are normative and therefore developed based on a low-risk population without known risk factors for fetal growth restriction. All multiple pregnancies, inductions, and primary cesarean sections were also excluded to approximate the optimal birth weight for each gestational age. More information can be found at www.perined.nl and in the following scientific publications: Hoftiezer L et al. Am J Obstet Gynecol. (2019) From population reference to national standard: new and improved birthweight charts. 10.1016/j.ajog.2018.12.023 Hoftiezer L et al. Eur J Pediatr. (2016) Defining small-for-gestational-age: prescriptive versus descriptive birthweight standards. 10.1007/s00431-016-2740-8 The curves were compiled by Liset Hoftiezer, guided by a working group consisting of representatives from various professional groups, birth care organizations, and researchers: Joyce Dijs-Elsinga, Jeroen van Dillen, Michel Hof, Marije Hogeveen, Chantal Hukkelhoven, Karline van de Kamp, Richard van Lingen, Alieke de Roon-Immerzeel, Rosalinde Snijders, Viki Verfaille, Ger de Winter, and Koos Zwinderman. The research position was financially supported by the Isala Innovation & Science Fund and Nutricia Early Life Nutrition; there has been no interference with the content of the project. Ā© 2024 Perined

About

ORReady

Features
Read full description

Build surgical knowledge with 5,900+ multiple-choice questions and clinical cases. ORReady helps medical students and junior doctors prepare for surgical rotations and exams through short, focused practice. • Learn from detailed explanations and source links. • Revisit weaker topics with smart reviews and mistake practice. • Study surgical topics for USMLE and MRCS preparation. • Practise trauma scenarios with timed exams and skills drills. • Build the basics with a 14-day surgery bootcamp. Study in English, Spanish, French, German or Dutch. No account required. For educational use only. Not a medical device. Does not provide diagnostic or treatment advice.

Screenshots

PRN Graph4 screens
ORReady4 screens

Verdict

The call

The clearest difference is update cadence: ORReady at every 10 days against PRN Graph's every 3 months. On price, ads, in-app purchases and device support there is nothing between them.

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

CostPrice Ā· In-app purchases Ā· Ads Ā· Monetization

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

UpkeepUpdate frequency

PRN Graph ships an update every 3 months, ORReady every 10 days. The most recent releases landed on November 1, 2026 and October 25, 2026 respectively.

Scorecard1 real difference Ā· 5 level
PRN Graph versus ORReady: the parameters behind the verdict, then further details
ParameterPRN GraphORReady
PriceFreeFree
Update frequencyEvery 3 monthsEvery 10 days — better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.015.0 — better
Further details — not scored
Size6 MB86 MB
Age rating17+17+
DeveloperGlamorous Goat B.V.Willem Knijnenburg

In-app purchases

None

PRN Graph

No in-app purchases

None

ORReady

No in-app purchases

Questions

Is PRN Graph free?
PRN Graph is free to download, with no in-app purchases.
Is ORReady free?
ORReady is free to download, with no in-app purchases.
Do PRN Graph or ORReady have ads?
Neither PRN Graph nor ORReady shows ads.
Which is updated more often, PRN Graph or ORReady?
PRN Graph ships an update every 3 months, and ORReady every 10 days. Most recently, PRN Graph was updated on November 1, 2026 and ORReady on October 25, 2026.

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