# Reaction Lab vs CDPD App

The clearest difference is update cadence: CDPD App at every 3 days against Reaction Lab's every 7 months. CDPD App also leads on iOS requirement (16.4 vs 18.0). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Reaction Lab sells 2 in-app purchases, starting at $1.99 per month and CDPD App sells 4 in-app purchases, starting at $2.99 per month. Whichever you choose, the download price is not the number that matters.

Reaction Lab ships an update every 7 months, CDPD App every 3 days. The most recent releases landed on September 26, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Reaction Lab | CDPD App |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/reaction-lab-reflex-tests/id6757831974/reviews)** | — |
| Number of ratings | **2** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 3 days** |
| Monetization | Free with in-app purchases | — |
| Size | 22 MB | 70 MB |
| Requires iOS | 18.0 | **16.4** |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Anthony Harvey](https://appshunter.io/developer/1478197285) | [Guilherme Lorenz](https://appshunter.io/developer/1136406077) |

## What reviewers say

### Reaction Lab

[App page](https://appshunter.io/ios/app/reaction-lab-reflex-tests/id6757831974)

Measure and improve your response speed with a suite of scientifically-inspired tests. Track progress over time with detailed analytics and gain insights into your performance in various situations. Designed for focus and privacy, all data stays on your device.

**Highlights:** Multiple reaction time test types, Visual, audio, and haptic cues, Grip-release and motion-based tests, Dual-task and fatigue tracking, Detailed session summaries and trend charts, On-device data privacy, Offline functionality

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| React Fast Monthly | $1.99 | per month |
| React Fast Yearly | $4.99 | per year |


### CDPD App

[App page](https://appshunter.io/ios/app/cdpd-app/id6788149144)

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plano Mensal | $2.99 | per month |
| Monthly subscription | $3.99 | per month |
| Assinatura trimestral | $9.99 | per 3 months |
| Assinatura Anual | $39.99 | per year |


## Frequently asked questions

### Is Reaction Lab free?

Reaction Lab is free to download, with in-app purchases available.

### Is CDPD App free?

CDPD App is free to download, with in-app purchases available.

### Do Reaction Lab or CDPD App have ads?

Neither Reaction Lab nor CDPD App shows ads.

### Which is updated more often, Reaction Lab or CDPD App?

Reaction Lab ships an update every 7 months, and CDPD App every 3 days. Most recently, Reaction Lab was updated on September 26, 2026 and CDPD App on October 4, 2026.

---

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