# CDP Knowledge Test vs Persimmon

The clearest difference is in-app purchases: Persimmon at none against CDP Knowledge Test's 2. Persimmon also leads on update cadence (every 3 weeks vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. CDP Knowledge Test sells 2 in-app purchases, starting at $11.99 per month. Persimmon asks for nothing beyond the download.

CDP Knowledge Test ships an update every 3 months, Persimmon every 3 weeks. The most recent releases landed on September 10, 2026 and June 11, 2026 respectively.

## The numbers

| Metric | CDP Knowledge Test | Persimmon |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/persimmon-research-simplified/id6747952930/reviews)** |
| Number of ratings | — | **2** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Monetization | — | Free |
| Size | 9 MB | 23 MB |
| Requires iOS | **17.2** | 18.1 |
| Devices | iPhone | **iPhone, iPad** |
| Age rating | 4+ | 12+ |
| Developer | [Cargo Teleport Inc](https://appshunter.io/developer/1761832181) | [Momenta Lab LLC](https://appshunter.io/developer/1615879512) |

## What reviewers say

### CDP Knowledge Test

[App page](https://appshunter.io/ios/app/cdp-knowledge-test/id6740606245)

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium monthly subscription | $11.99 | per month |
| Lifetime version | $24.99 | one-time |


### Persimmon

[App page](https://appshunter.io/ios/app/persimmon-research-simplified/id6747952930)

This app simplifies complex scientific research papers from arXiv and SocArXiv using AI. It offers customizable summaries tailored to your expertise level and allows you to search, save, and get daily updates on new publications. You can also use it as a basic preprint browser without AI.

**Highlights:** AI-powered paper summaries, Customizable AI models and expertise levels, Search arXiv and SocArXiv, Save papers for offline access, Daily updates and notifications, Privacy-focused, no data collection

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is CDP Knowledge Test free?

CDP Knowledge Test is free to download, with in-app purchases available.

### Is Persimmon free?

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

### Do CDP Knowledge Test or Persimmon have ads?

Neither CDP Knowledge Test nor Persimmon shows ads.

### Which is updated more often, CDP Knowledge Test or Persimmon?

CDP Knowledge Test ships an update every 3 months, and Persimmon every 3 weeks. Most recently, CDP Knowledge Test was updated on September 10, 2026 and Persimmon on June 11, 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.*