# OTR Prep vs ARDMS

The clearest difference is in-app purchases: ARDMS at none against OTR Prep's 1. ARDMS also leads on iOS requirement (13.0 vs 16.6). OTR Prep's advantage is ads (none vs shown). On price and device support there is nothing between them.

Both are free to download. OTR Prep sells 1 one-off in-app purchase. ARDMS asks for nothing beyond the download.

## The numbers

| Metric | OTR Prep | ARDMS |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 5 months | — |
| Size | 21 MB | 30 MB |
| Requires iOS | 16.6 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [iAPPSSTUDIO](https://appshunter.io/developer/1830642259) | [Muhammad Abid](https://appshunter.io/developer/1491892215) |

## What reviewers say

### OTR Prep

[App page](https://appshunter.io/ios/app/otr-prep-nbcot-practice-test/id6760580880)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Get Lifetime Access | $7.99 | one-time |


### ARDMS

[App page](https://appshunter.io/ios/app/ardms/id6794798201)

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

**In-app purchases:** none


## Frequently asked questions

### Is OTR Prep free?

OTR Prep is free to download, with in-app purchases available.

### Is ARDMS free?

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

### Do OTR Prep or ARDMS have ads?

ARDMS shows ads; OTR Prep does not.

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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.*