Comparison

Preop Eval vs Dermoscopy Two Step Algorithm

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

Head to head
About

Preop Eval

This app provides guidance for evaluating and preparing adult patients for non-cardiac surgery. It includes algorithms and resources on medication management, cardiac event timing, and preoperative testing, serving as both a reference and a teaching tool for medical professionals.

Highlights
  • Cardiac evaluation algorithm
  • Medication guidance (starting/stopping)
  • Surgery timing after cardiac events
  • Preoperative testing recommendations
  • Review for students and residents
  • Perioperative insulin management
Features
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Preop Eval organizes and presents much of the guidance that one needs in order to evaluate and prepare adult patients for non-cardiac surgery. It is based upon the guidelines on this topic from the American College of Cardiology, the European Society of Anaesthesiology, the American Society of Anesthesiologists, the Institute for Clinical Systems Improvement, the American College of Chest Physicians, and more (full references in the app). The app contains 1 algorithm and 3 resources: the cardiac evaluation algorithm, guidance on starting and stopping key medications in the perioperative period, guidance on timing of surgery after cardiac events, and guidance on preoperative testing. It also contains a review of preoperative evaluation mainly for students and residents. The app addresses such common questions as: - who needs bloodwork before surgery? - who needs an EKG or a CXR? - how do I handle patients on warfarin, clopidogrel, and DOAC's? - which patients need adjustment of perioperative insulin and diabetic meds, and how? - which active cardiac conditions preclude surgery? - how long after MI or stent should a patient wait before surgery? - are there adjustments to make on psych meds, rheumatologic meds, ACE's and ARB's? This app is written and intended for practicing physicians like internists, family physicians, and hospitalists; for resident physician trainees; and for medical students. In addition to being a reference, the algorithm is written to be a teaching tool by not just delivering an answer, but instead walking a physician through the evaluation process so that one learns that process along the way. As an educator and clinician, I am interested in feedback and I would be grateful for guidance on improving the tool.

About

Dermoscopy Two Step Algorithm

This app guides healthcare professionals in interpreting dermoscopic patterns to identify skin lesions. It uses a series of questions and provides over 80 images and charts to aid in diagnosis. Interactive cases are included for practice.

Highlights
  • Dermoscopic pattern interpretation
  • Question-based diagnostic guidance
  • Over 80 photos and charts
  • 50 interactive diagnostic cases
  • Offline functionality
  • Melanocytic and non-melanocytic lesion analysis
Features
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This app is intended to help you interpret the dermoscopic patterns seen with your dermatoscope. You will be asked a series of questions that will lead you to the most probable diagnosis. This app also contains over 80 photos and charts to help you in your diagnosis. No internet connection needed to view the full app. It is all ready for super quick image and information retrieval. There are also 50 interactive cases to solve. Each case starts with a clinical and dermoscopic image and ends with a labelled dermoscopic image pointing out critical structures. This app is based on the 2 step algorithm with the first step involving the determination of whether the lesion is a melanocytic. Melanocytic lesions will be divided into nevi or lesions with varying levels of suspicion for melanoma based on melanoma specific patterns and common nevi patterns. Non-melanocytic lesions will be analyzed to determine if they are suspicious for basal cell carcinoma or squamous cell carcinoma. Common benign lesions such as dermatofibroma, seborrheic keratoses and hemangiomas will be positively identified to avoid unnecessary biopsies. This app will increase your ability to detect skin cancers with greater accuracy thereby decreasing unnecessary biopsies and missing less early melanomas and nonmelanoma skin cancers. Check out https://usatinemedia.com to learn more and watch a video demo of this app narrated by Dr. Richard P. Usatine. Authors: Ashfaq A. Marghoob, MD Memorial Sloan-Kettering Cancer Center New York, New York Richard P. Usatine, MD University of Texas Health Science Center San Antonio, Texas Natalia Jaimes, MD Aurora Skin Cancer Center and Universidad Pontificia Bolivariana Medellin, Colombia To learn more dermoscopy from these authors, see www.americandermoscopy.com. Disclaimer: This app is intended for the education of healthcare professionals and not as a diagnostic and treatment reference for the general population. Disclaimer: While this app may help you in rendering a correct diagnosis, it is not intended to entirely replace the findings on patient history and physical examination including examination of the lesion with side lighting and touch. The final diagnosis rests on properly assimilating the information gained from the patient history, thorough naked eye physical examination, and meticulous dermoscopic inspection of the lesion. 3Gen, Inc. is the sponsor of this app. Visit www.dermlite.com to see their complete line of skin imaging devices. Developed by Usatine Media Richard P. Usatine, MD, Co-President, Professor of Family & Community Medicine, Professor of Dermatology and Cutaneous Surgery, University of Texas Health San Antonio Peter Erickson, Co-President, Lead Software Developer

Screenshots

Preop Eval4 screens
Dermoscopy Two Step Algorithm4 screens

Verdict

The call

The clearest difference is review sentiment: Dermoscopy Two Step Algorithm at 100% against Preop Eval's 67%. Dermoscopy Two Step Algorithm also leads on ratings volume (10 vs 2) and iOS requirement (10.0 vs 16.6). Preop Eval's advantage is rating (5.0 vs 4.6). On price, update cadence, ads and in-app purchases 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

Preop Eval holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Dermoscopy Two Step Algorithm has 10 ratings behind it against 2, so its average is the more settled of the two. Written reviews complicate that: 67% of Preop Eval's written reviews are positive against 100% of Dermoscopy Two Step Algorithm's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Preop Eval ships an update every 6 months, Dermoscopy Two Step Algorithm every 5 months. The most recent releases landed on September 10, 2026 and September 11, 2026 respectively.

Scorecard4 real differences · 6 level
Preop Eval versus Dermoscopy Two Step Algorithm: the parameters behind the verdict, then further details
ParameterPreop EvalDermoscopy Two Step Algorithm
PriceFreeFree
Rating5.0 (2 ratings) — better4.6 (10 ratings)
Positive reviews66.7% of reviews100.0% of reviews — better
Number of ratings210 — better
Update frequencyEvery 6 monthsEvery 5 months — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS16.610.0 — better
Further details — not scored
Size15 MB220 MB
Age rating17+17+
DeveloperUnited Health Services, Inc.Usatine & Erickson Media LLC

Customer experience

Preop Eval

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews12 reviews
Positive66.7%
Neutral8.3%
Negative25.0%

Dermoscopy Two Step Algorithm

All ratings10 ratings
Positive90.0%
Neutral0.0%
Negative10.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Preop Eval

No in-app purchases

None

Dermoscopy Two Step Algorithm

No in-app purchases

Questions

Is Preop Eval free?
Preop Eval is free to download, with no in-app purchases.
Is Dermoscopy Two Step Algorithm free?
Dermoscopy Two Step Algorithm is free to download, with no in-app purchases.
Which has better reviews, Preop Eval or Dermoscopy Two Step Algorithm?
Preop Eval is rated higher. Preop Eval averages 5.0 out of 5 from 2 ratings, while Dermoscopy Two Step Algorithm averages 4.6 from 10 ratings.
Do Preop Eval or Dermoscopy Two Step Algorithm have ads?
Neither Preop Eval nor Dermoscopy Two Step Algorithm shows ads.
Which is updated more often, Preop Eval or Dermoscopy Two Step Algorithm?
Preop Eval ships an update every 6 months, and Dermoscopy Two Step Algorithm every 5 months. Most recently, Preop Eval was updated on September 10, 2026 and Dermoscopy Two Step Algorithm on September 11, 2026.

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