# Harriet Lane Handbook vs PREP Self

The clearest difference is rating: Harriet Lane Handbook at 4.8 against PREP Self's 3.7. Harriet Lane Handbook also leads on ratings volume (601 vs 9). PREP Self's advantage is in-app purchases (none vs 2) and update cadence (daily vs every 7 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Harriet Lane Handbook sells 2 in-app purchases, starting at $39.99 per year. PREP Self asks for nothing beyond the download.

Harriet Lane Handbook holds the better App Store score, 4.8 against 3.7. That said, the two scores are not equally well evidenced: Harriet Lane Handbook has 601 ratings behind it against 9, so its average is the more settled of the two. Written reviews complicate that: 57% of Harriet Lane Handbook's written reviews are positive against 67% of PREP Self's, so the app with the better star average is not the one people write more warmly about.

Harriet Lane Handbook ships an update every 7 months, PREP Self daily. The most recent releases landed on October 23, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Harriet Lane Handbook | PREP Self |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (601 ratings)](https://appshunter.io/ios/app/harriet-lane-handbook/id458365685/reviews)** | [3.7 (9 ratings)](https://appshunter.io/ios/app/prep-self-assessments-program/id6756599702/reviews) |
| Number of ratings | **601** | 9 |
| Positive reviews | 57.1% of reviews | **66.7% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 7 months | **Daily** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 15 MB | 44 MB |
| Requires iOS | **15.0** | 15.6 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [Unbound Medicine, Inc.](https://appshunter.io/developer/300420400) | [American Academy of Pediatrics](https://appshunter.io/developer/409863343) |

## What reviewers say

### Harriet Lane Handbook

[App page](https://appshunter.io/ios/app/harriet-lane-handbook/id458365685)

This comprehensive pediatric resource offers an updated drug formulary, disease information, and management guidelines. It includes integrated calculators, visual exploration of medical literature, and the ability to bookmark favorite entries for quick access.

**Highlights:** Updated pediatric drug formulary, Hundreds of pediatric conditions, Integrated dosage calculators, Prime PubMed search, Management recommendations & immunization schedules, Highlighting and note-taking, Visual exploration of medical literature

**Features:** Vision Pro support

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Davis's Drug Guide | $39.99 | per year |
| Harriet Lane 23rd edition | $59.99 | one-time |

**What reviewers like**

- 👍 Great source of information
- 👍 Handy to have on phone
- 👍 Use daily
- 👍 Love saving favorites
- 👍 Formulary and expanded drug search

**What reviewers complain about**

- 👎 Lousy liquid po dose calc
- 👎 Lacks neonate sodium levels
- 👎 No pediatrics dosage calculator
- 👎 Still not a finished product
- 👎 Missing reference values

**Reported bugs**

- App won't open after iOS 11 update
- Content inaccessible without wifi
- Resolution fuzzy and ugly
- Content orientation bizarre
- Cannot open content

**Requested features**

- Sliders for ped dose calc
- More search power for simpler terms
- Dark mode option
- Advanced analytics dashboard


### PREP Self

[App page](https://appshunter.io/ios/app/prep-self-assessments-program/id6756599702)

Access trusted pediatric learning content through a new mobile app. Build a personalized question bank by selecting blocks from various content areas to fit your learning style and schedule. Earn CME credits and MOC points with each block.

**Highlights:** Trusted PREP content, Customizable question bank, Case-based questions, Earn CME credits, Earn MOC points, Modern user interface

**In-app purchases:** none


## Frequently asked questions

### Is Harriet Lane Handbook free?

Harriet Lane Handbook is free to download, with in-app purchases available.

### Is PREP Self free?

PREP Self is free to download, with no in-app purchases.

### Which has better reviews, Harriet Lane Handbook or PREP Self?

Harriet Lane Handbook is rated higher. Harriet Lane Handbook averages 4.8 out of 5 from 601 ratings, while PREP Self averages 3.7 from 9 ratings.

### Do Harriet Lane Handbook or PREP Self have ads?

Neither Harriet Lane Handbook nor PREP Self shows ads.

### Which is updated more often, Harriet Lane Handbook or PREP Self?

Harriet Lane Handbook ships an update every 7 months, and PREP Self daily. Most recently, Harriet Lane Handbook was updated on October 23, 2026 and PREP Self on October 24, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*