# CPEN Practice Test vs PDB Viewer

CPEN Practice Test and PDB Viewer are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. CPEN Practice Test sells 1 in-app purchase, starting at $9.00 per month and PDB Viewer sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | CPEN Practice Test | PDB Viewer |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | — | Monthly |
| Size | 3 MB | 2 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Ambitionz Apps](https://appshunter.io/developer/1764753535) | [Qvyshift LLC](https://appshunter.io/developer/1536442361) |

## What reviewers say

### CPEN Practice Test

[App page](https://appshunter.io/ios/app/cpen-practice-test/id6757288558)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| CPEN Practice Test | $9.00 | per month |


### PDB Viewer

[App page](https://appshunter.io/ios/app/pdb-viewer-3d-molecules/id6777468488)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| PDB Viewer Pro | $9.99 | one-time |


## Frequently asked questions

### Is CPEN Practice Test free?

CPEN Practice Test is free to download, with in-app purchases available.

### Is PDB Viewer free?

PDB Viewer is free to download, with in-app purchases available.

### Do CPEN Practice Test or PDB Viewer have ads?

Neither CPEN Practice Test nor PDB Viewer shows ads.

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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.*