Lanthier vs Diagnosaurus® DDx
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Lanthier
Access up-to-date internal medicine information and guidelines quickly and efficiently. This app offers a fast search function, intuitive menus, and direct links to PubMed references. It's designed for physicians, residents, and medical students to use at the bedside.
- Concise bedside information
- Advanced search function
- Intuitive menus
- Direct links to PubMed
- Personal note-taking
- Cross-device synchronization
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“Lanthier” is an internal medicine app based on the seventh edition of the bestselling pocketbook. Completely re-imagined for iOS, this app will allow any physician, resident or medical student to access up-to-date medical information and guidelines quickly and efficiently. Free 7 days trial subscription! “Lanthier Practical Guide to Internal Medicine is a good choice for an app to replace your pocketbook. Beyond providing quality content with references, it has an excellent design that makes it more than just a digitized version of a book. Finding clinically relevant information about a condition is quick and easy.” iMedicalApp.com — FEATURES — • Concise: edited to be useful at the bedside. • Fast: advanced search function, intuitive menus. • Direct link to the references on PubMed and now through Read by QxMD (internet connection required). Build your paper collection using articles selected by Dr Lanthier himself. • MedCalX integration (sold separately): for quick access to the trusted medical calculator. • Take personal notes within the topics and synchronize them across your iOS devices. Perfect for studying for board exams! — TOPICS — Cardiology Dermatology (new) Endocrinology Gastroenterology General Internal Medicine Hematology Infectious Diseases Nephrology Neurology Oncology Pneumology Rheumatology — ABOUT THE LEAD AUTHORS — Dr Luc Lanthier practices General Internal Medicine at the Sherbrooke University Hospital Center and is a Professor of Medicine at the Faculty of Medicine and Health Sciences of the University of Sherbrooke. He is former chair of the French Examination Board for Internal Medicine Exam at the Royal College of Physicians and Surgeons of Canada. Dr Donald Echenberg practices General Internal Medicine at the Sherbrooke University Hospital Center and is an Associate Professor of Medicine at the Faculty of Medicine and Health Sciences of the University of Sherbrooke. He is past president of the Canadian Society of Internal Medicine and is currently Governor of the Quebec Chapter of the American College of Physicians. — DISCLAIMER — This publication (application) is to be used as a guide only. It is intended only for use by licensed medical practitioners and medical students. Every doctor (or prescriber) is responsible for their actions. Therapeutic options presented in this guide reflect current approaches and guidelines in the field of internal medicine. Content has been peer reviewed by leading experts in their respective fields. The authors of Lanthier - Practical Guide to Internal Medicine shall not be liable for any injury and/or damage to persons or property arising from the use of this application. This guide is not meant to replace clinical judgment. It is the responsibility of the licensed prescriber to verify the indications, contraindications and dosage of the medication (and actions) they prescribe. — ABOUT SUBSCRIPTION — Lanthier - Internal Medicine is offered as a subscription service, renewed automatically. Payment will be charged to iTunes Account at confirmation of purchase. The subscription will automatically renew unless auto-renew is turned off at least 24-hours before the end of the current period. The iTunes Account will be charged for renewal within 24-hours prior to the end of the current period. Subscriptions may be managed by the user and auto-renewal may be turned off by going to the application «Settings» section and tapping «Manage Subscriptions» after purchase. For more information on Terms of Use visit https://lanthiermed.com/terms-of-use
Diagnosaurus® DDx
This medical reference tool assists healthcare professionals in performing differential diagnoses quickly and confidently. It offers a searchable database of over 1,000 diagnoses, cross-referenced for related conditions, and allows users to save favorite entries and make custom notes.
- Over 1,000 differential diagnoses
- Search by organ system, symptom, or disease
- See Related DDx feature
- Save favorite entries
- Highlight and make custom notes
- Universal Index Search
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** Top-Selling App Used by Tens of Thousands of Health Professionals, Worldwide ** ABOUT DIAGNOSAURUS DDX This quick-reference tool helps healthcare professionals perform differential diagnosis with speed and confidence at the point of care. With Diagnosaurus you can quickly search over 1,000 diagnoses by organ system, symptom, or disease, or you can view all entries. Use the valuable “See Related DDx” feature within each entry to consider alternative diagnoses and quickly link to those entries. The convenient “Favorites” feature allows you to save specific searches and bookmark in your personal archive. FEATURES • More than 1,000 differential diagnoses • Highlight and make custom notes within entries • Entries organized in quick-read format • “See Related DDx” links to other potential diagnoses • Disease, symptom, and organ system indexes • “Favorites” for bookmarking important entries • Universal Index Search to help find answers fast Author: Roni F. Zeiger, MD Publisher: McGraw-Hill Medical Powered by: Unbound Medicine
Screenshots
Verdict
The clearest difference is rating: Diagnosaurus® DDx at 4.8 against Lanthier's 3.8. Diagnosaurus® DDx also leads on monetization model (free with in-app purchases vs subscription) and ratings volume (2.5K vs 5). Lanthier's advantage is update cadence (every 2 months vs every 10 months) and review sentiment (62% vs 53%). On price, ads, in-app purchases and iOS requirement 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
Both are free to download. Lanthier sells 2 in-app purchases, starting at $19.49 per year and Diagnosaurus® DDx sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.
Diagnosaurus® DDx holds the better App Store score, 4.8 against 3.8. That said, the two scores are not equally well evidenced: Diagnosaurus® DDx has 2.5K ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 62% of Lanthier's written reviews are positive against 53% of Diagnosaurus® DDx's, so the app with the better star average is not the one people write more warmly about.
Lanthier ships an update every 2 months, Diagnosaurus® DDx every 10 months. The most recent releases landed on October 14, 2026 and October 17, 2026 respectively.
| Parameter | Lanthier | Diagnosaurus® DDx |
|---|---|---|
| Price | Free | Free |
| Rating | 3.8 (5 ratings) | 4.8 (2.5K ratings) — better |
| Positive reviews | 61.9% of reviews — better | 53.2% of reviews |
| Number of ratings | 5 | 2.5K — better |
| Update frequency | Every 2 months — better | Every 10 months |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Subscription | Free with in-app purchases — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 16.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 70 MB | 18 MB |
| Age rating | 17+ | 17+ |
| Developer | Les Éditions Formed inc. | Unbound Medicine, Inc. |
Customer experience
Lanthier
Diagnosaurus® DDx
Bugs and requests
Lanthier
Not enough reviews yet to summarise bugs or requests.
Diagnosaurus® DDx
Reported bugs
3 issues- Subscription issues and inability to restore purchases
- Blank pages and non-functional content
- Compatibility issues with newer iOS versions
Requested features
5 requests- Add ability to edit or add custom differential diagnoses
- Improve search functionality and navigation
- Provide more detailed information on conditions
- Integrate with other medical resources and databases
- Improve support for older devices and iOS versions
In-app purchases
Lanthier
- Lanthier - current users3 Months trial$19.491 Year
- Lanthier - new users7 Days trial$19.491 Year
Diagnosaurus® DDx
- Diagnosaurus DDx$4.99









