# What Doctors Know vs PROTECT

The clearest difference is in-app purchases: PROTECT at none against What Doctors Know's 14. What Doctors Know's advantage is iOS requirement (13.0 vs 15.0). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. What Doctors Know sells 14 in-app purchases, starting at $5.99 per year. PROTECT asks for nothing beyond the download.

What Doctors Know ships an update every 4 months, PROTECT every 6 months. The most recent releases landed on October 6, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | What Doctors Know | PROTECT |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 6 months |
| Size | 12 MB | 39 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 4+ |
| Developer | [PressPad Sp. z o.o.](https://appshunter.io/developer/449000752) | [NICST](https://appshunter.io/developer/1611317309) |

## What reviewers say

### What Doctors Know

[App page](https://appshunter.io/ios/app/what-doctors-know/id880982965)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (14)**

| Purchase | Price | Billing |
| --- | --- | --- |
| What Doctors Know | $5.99 | per year |
| Issue #1 | $0.99 | one-time |
| Issue #2 | $0.99 | one-time |
| Issue #3 | $0.99 | one-time |
| Issue #95 | $0.99 | one-time |
| Issue #96 | $0.99 | one-time |
| Issue #97 | $0.99 | one-time |
| Issue #98 | $0.99 | one-time |
| Issue #99 | $0.99 | one-time |
| Issue #100 | $0.99 | one-time |
| Issue #91 | $0.99 | one-time |
| Issue #92 | $0.99 | one-time |
| Issue #93 | $0.99 | one-time |
| Issue #94 | $0.99 | one-time |


### PROTECT

[App page](https://appshunter.io/ios/app/protect-icu/id1611317307)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is What Doctors Know free?

What Doctors Know is free to download, with in-app purchases available.

### Is PROTECT free?

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

### Do What Doctors Know or PROTECT have ads?

Neither What Doctors Know nor PROTECT shows ads.

### Which is updated more often, What Doctors Know or PROTECT?

What Doctors Know ships an update every 4 months, and PROTECT every 6 months. Most recently, What Doctors Know was updated on October 6, 2026 and PROTECT on October 25, 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.*