Histo! vs OnERcall
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Histo!
This medical study aid helps users learn and test their knowledge of histology. It features a vast library of identification slides, interactive learning modes, and a search function for efficient study.
- 2179 identification slides
- 19 Main Topics and 148 Subtopics
- Offline functionality
- Labeled slide mode with interactive labels
- Learn, Quiz, and Test modes
- Marking and review of slides
- Searchable keywords
Read full descriptionHide full description
Histo! helps you learn histology and test your knowledge. It is the favorite study aid of medical and dental students in histology courses at the University of Utah. The App currently contains 2179 identification slides, based on 547 photomicrographic images. It is organized into 19 Main Topics and 148 Subtopics. It does not require an internet connection. NAVIGATION •Three navigation menus are provided, one to choose among the Main Topics, a second to select Subtopics of the Main Topics, and a Search feature to find slides using 675 keywords. These meus allow you focus your study as broadly or narrowly as desired. •Once slides are displayed, a one-finger left or right swipe moves forward or backward by one slide, a two-finger swipe jumps 10 slides. LABELED SLIDE MODE •This mode presents 92 micrographs that cover the Main Topics. Important structural features are named, and short explanations are given. These micrographs provide an efficient way for anyone new to a topic to quickly learn the identifications and spatial relationships of the microanatomy that are key for identifying tissues and organs. •The labels can be turned on and off by tapping, allowing immediate self-testing while learning. LEARN, QUIZ, and TEST (LQT) MODES •These modes are based on 2087 questions and answers related to 455 micrographs. •In the Learn mode, each slide displays a question, the answer, and a short explanation. The slides are presented in a logical order that helps you learn the material. •In the Quiz mode, only the question is shown, and the order of presentation is randomized. You can tap to see the answer and explanation. A Quiz persists until the user deletes it. •In the Test mode, you tap to display the built-in keyboard to answer the question, then grade your response. Results for each Main Topic are shown when you have finished a Test. STRUCTURES AND ADDITIONAL FEATURES •Histo! addresses both microanatomy and functional histology. About 70% of the LQT slides ask for identification of structures, the remainder are related to other features of these structures, such as functions, molecular components, or diseases. •From the Main Topic menu, you choose whether to review structures or other features, or both. MARKING AND UNMARKING SLIDES •Slides in any mode may be marked for later review. This happens automatically when you miss a question in the Test mode, and by tapping a button in the Label, Learn, or Quiz modes. •Whenever you return to the Start screen, either during a session or later after exiting, you are offered the chance to review slides marked in any of the four modes. Buttons to review marked slides are also present on the Main and Subtopics menus. •Slides that have been marked can be unmarked during a review by scoring the question as completely correct in the Test mode or tapping a button in the Learn or Quiz modes. SHOWING SPECIFIC SLIDES •Identifiers for slides viewed in the Labeled, Learn or Quiz modes can be recorded and then distributed via electronic documents. Anyone importing these identifiers can view the slides in the Learn mode. •Students can ask for help with a structural or functional question related to a specific slide and instructors can present preselected examples to an individual or group.
OnERcall
Connect with a US-licensed Emergency Medicine Physician 24/7 for non-severe medical concerns. Get quick answers, diagnoses, and prescriptions without insurance or monthly fees. Avoid ER visits for minor issues.
- 24/7 physician access
- Video and audio consultations
- Diagnosis and treatment plans
- Prescription services
- HIPAA compliant
- Flat fee per visit
Read full descriptionHide full description
OnERcall allows you to quickly speak or video chat directly with a US-licensed, Board Certified Emergency Medicine Physician, 24/7 and 365 days a year. Within minutes, you will get the answers you need to non-severe issues from wherever you are, whenever you need. OnERcall app is free to download and register and has no monthly fees. No insurance is required as there is one flat fee per visit. All you need is the app or website and an internet connection. You can use your phone, tablet or desktop computer to create an account and request a visit. With OnERcall, you can check with an Emergency Medicine Physician before you head to the Emergency room. Not sure if your “emergency” needs immediate attention? We are here to help. Worried that non-severe symptoms could lead to something more serious? We are here to help. We aim to minimize the stress and exposure in common instances where healthcare help is needed but in a less emergent way. Avoid the hassle, waiting time and unexpected costs of walk-in clinics, urgent cares or Emergency Rooms. Get the peace of mind you need before you leave your home or other location with our secure and HIPAA compliant video and audio tools. Easy as 1-2-3 1. Register now: Download app or use the website to create your account. You can add any dependents 17 and under for treatment. You may also add your or their personal history for a more detailed examination. 2. Request a visit: Securely submit your payment then create your visit request for an immediate video chat or phone call with our friendly, caring and compassionate Emergency Medicine Physicians, who are experts in their field. 3. On track to better health: Get treated by one of our doctors, who will put you on the right path to better health! Our OnERcall Emergency Physicians can help diagnose symptoms and offer treatment and follow up strategies as needed. We are able to prescribe some medications, when necessary. Prescriptions will be sent directly to your preferred pharmacy. Examples of what we treat include, but are not limited to, allergies, bruises, cuts, minor burns, fevers, coughs, colds, flu, mild Covid-19 symptoms, headaches, rashes, hives, sprains, joint pain, diarrhea, urinary tract infections and more. Safety: OnERcall features secure and HIPAA compliant video and audio tools Patient accounts are secure and are accessed using one-time login passwords (OTP) We only employ Board Certified Emergency Medicine physicians who are friendly, caring, compassionate, and experts in Emergency Medicine Affordable and Transparent: OnERcall app is free to download and register There are no monthly fees for using the app or website We treat everyone for one flat fee of $50 for each visit. Avoid insurance premiums and the unknown costs of walk-in clinics, urgent cares, and Emergency Rooms. Follow-up calls for specific cases may be scheduled for $25. Through patient accounts, patients have access to their past call history and can add or edit their past medical history, add or edit dependents, set up their preferred pharmacy and edit payment methods. We are currently available to answer calls for patients in Maryland. Washington, D.C. or Virginia. This list will be updated periodically as coverage grows. To learn more and get your questions answered, you can visit our website at onercall.com or email us at admin@onercall.com. If you are having a medical emergency, please call 911.
Screenshots
Verdict
The clearest difference is price: OnERcall at Free against Histo!'s $9.99. OnERcall also leads on update cadence (every 6 weeks vs every 11 months). Histo!'s advantage is iOS requirement (13.0 vs 15.0). On rating, review sentiment, ratings volume and ads 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
OnERcall is free to download; Histo! costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for Histo! against 5.0 for OnERcall. Both are backed by a comparable volume of ratings — 29 and 14 respectively. Written reviews split almost evenly too, at 100% and 100% positive.
Histo! ships an update every 11 months, OnERcall every 6 weeks. The most recent releases landed on October 15, 2026 and September 15, 2026 respectively.
| Parameter | Histo! | OnERcall |
|---|---|---|
| Price | $9.99 | Free — better |
| Rating | 5.0 (29 ratings) | 5.0 (14 ratings) |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| Number of ratings | 29 — better | 14 |
| Update frequency | Every 11 months | Every 6 weeks — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free with in-app purchases — better |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 13.0 — better | 15.0 |
| Further details — not scored | ||
| Size | 456 MB | 125 MB |
| Age rating | 12+ | 17+ |
| Developer | John Ash | OnERcall |
Customer experience
Histo!
OnERcall
In-app purchases
Histo!
No in-app purchases
OnERcall
No in-app purchases







