# Zeta Sigma Lambda vs Building a Second Brain

The clearest difference is update cadence: Zeta Sigma Lambda at every 2 months against Building a Second Brain's every 4 months. Zeta Sigma Lambda also leads on iOS requirement (12.0 vs 16.4). On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Zeta Sigma Lambda ships an update every 2 months, Building a Second Brain every 4 months. The most recent releases landed on October 8, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Zeta Sigma Lambda | Building a Second Brain |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.7 (15 ratings)](https://appshunter.io/ios/app/building-a-second-brain/id6744942882/reviews)** |
| Number of ratings | — | **15** |
| Positive reviews | — | 50.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 2 months** | Every 4 months |
| Monetization | — | Free |
| Size | 79 MB | 90 MB |
| Requires iOS | **12.0** | 16.4 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 17+ | 17+ |
| Developer | [Ricardo Cumberbatch](https://appshunter.io/developer/1455104172) | [Forte Labs, LLC](https://appshunter.io/developer/1810064260) |

## What reviewers say

### Zeta Sigma Lambda

[App page](https://appshunter.io/ios/app/zeta-sigma-lambda/id6450674777)

**Features:** macOS Compatibility, Apple Wallet

**In-app purchases:** none


### Building a Second Brain

[App page](https://appshunter.io/ios/app/building-a-second-brain/id6744942882)

This app helps you manage information overload and achieve your goals through personal knowledge management. Connect with a community focused on productivity and digital organization for a more peaceful and purposeful life.

**Highlights:** PARA Method Mini-Course, Community Hub, Exclusive event invitations, Notetaking and creativity resources, Gateway to comprehensive courses

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

**In-app purchases:** none


## Frequently asked questions

### Is Zeta Sigma Lambda free?

Zeta Sigma Lambda is free to download, with no in-app purchases.

### Is Building a Second Brain free?

Building a Second Brain is free to download, with no in-app purchases.

### Do Zeta Sigma Lambda or Building a Second Brain have ads?

Neither Zeta Sigma Lambda nor Building a Second Brain shows ads.

### Which is updated more often, Zeta Sigma Lambda or Building a Second Brain?

Zeta Sigma Lambda ships an update every 2 months, and Building a Second Brain every 4 months. Most recently, Zeta Sigma Lambda was updated on October 8, 2026 and Building a Second Brain on October 24, 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.*