# DoCube vs SecondBrain Pro

The clearest difference is update cadence: DoCube at every 3 weeks against SecondBrain Pro's every 2 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. DoCube sells 1 one-off in-app purchase and SecondBrain Pro sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

DoCube ships an update every 3 weeks, SecondBrain Pro every 2 months. Both last shipped on October 24, 2026.

## The numbers

| Metric | DoCube | SecondBrain Pro |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (11 ratings)](https://appshunter.io/ios/app/docube-pdf-reader-and-notes/id6470183496/reviews)** | — |
| Number of ratings | **11** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Every 3 weeks** | Every 2 months |
| Monetization | Free with in-app purchases | — |
| Size | 104 MB | 10 MB |
| Requires iOS | 17.0 | 17.0 |
| Devices | **iPhone, iPad, Mac** | iPhone, iPad |
| Age rating | 17+ | 4+ |
| Developer | [Hangzhou Wenxu Interactive Technology Co., Ltd](https://appshunter.io/developer/1686869575) | [Heinrich Krupp](https://appshunter.io/developer/1866842398) |

## What reviewers say

### DoCube

[App page](https://appshunter.io/ios/app/docube-pdf-reader-and-notes/id6470183496)

This app transforms reading into knowledge retention with features like multi-tab browsing, precise document navigation, and versatile annotation tools. It supports various formats and converts highlights into flashcards for effective memorization and review.

**Highlights:** Multi-tab reading for multiple documents, Precise document positioning and history navigation, Support for PDF, EPUB, Markdown, and web pages, Six annotation tools including highlights and notes, Cross-document linking for knowledge networks, Automatic flashcard creation from highlights, AI-enhanced card generation

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full-platform Professional Edition | $34.99 | one-time |


### SecondBrain Pro

[App page](https://appshunter.io/ios/app/secondbrain-pro/id6757423935)

**Features:** macOS Compatibility, Family Sharing

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Standard | $7.99 | one-time |
| SecondBrain PREMIUM | $17.99 | one-time |


## Frequently asked questions

### Is DoCube free?

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

### Is SecondBrain Pro free?

SecondBrain Pro is free to download, with in-app purchases available.

### Do DoCube or SecondBrain Pro have ads?

Neither DoCube nor SecondBrain Pro shows ads.

### Which is updated more often, DoCube or SecondBrain Pro?

DoCube ships an update every 3 weeks, and SecondBrain Pro every 2 months. Most recently, DoCube was updated on October 24, 2026 and SecondBrain Pro on October 24, 2026.

---

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