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The best second brain apps in 2026 Where your notes live, and how they get in.

Tiago Forte coined "second brain" and defines it as "an external, centralized, digital repository for the things you learn and the resources from which they come." An app earns the name if it keeps your notes, links them and finds them again. These eight each do one part of that on an iPhone.

Jacky Fakkeldij Building Driftto, on his own · Updated 23 October 2026

I build Driftto, and it is on this list. Not at the top: it does one job, getting a note from your iPhone into a Notion second brain, so that is where it sits. Of the other apps here only Notion is a place Driftto writes to, and I say so for each of the rest. Every one of them is an app I would point a friend to.

The list has two parts. First six apps that can hold a second brain on an iPhone: notes, links between them, and a way to find them again. Then two that get things into one. In October 2026 I went through each app's help center, pricing page and US App Store listing.

The short list

Six of these hold a second brain: Notion and Tana Outliner for people who build their own structure, Obsidian and Logseq for plain files, Capacities for structure that is ready, and Apple Notes for nothing to install. Two get things in: Driftto, which sends a note straight to Notion, and Readwise, which exports what you read.

The best second brain apps in 2026, at a glance
Rank	App	Best for	Price
Where your second brain lives
1	Notion	A second brain you shape yourself	Free for one person
2	Obsidian	Plain Markdown files you own	Free, Sync $4 a month
3	Capacities	Notes as typed objects: people, books	Free, or $9.99 a month
4	Tana Outliner	Typed outline notes, built for voice	Free, or from $8 a month
5	Apple Notes	Already on your iPhone, with tags	Included with iOS
6	Logseq	An open-source outliner on plain files	Free
Getting things in
7	Driftto	Straight into your Notion database	From $2.99 a month
8	Readwise	Highlights from your reading, exported	$9.99 a month, yearly

Where your second brain lives Six apps that can hold your notes and link them.

1 Notion

Notion Labs · iPhone, iPad, Android, web

The most flexible place to build a second brain, and the only one on this list that Driftto writes to.

Price: Free for one person: unlimited pages and blocks, 7 days of page history, 5 MB per uploaded file. Plus costs $11.99 a month in the US App Store.
Works on: iPhone, iPad, Android and the web.
Capture: A Home Screen widget and a Siri or Action button shortcut open Notion AI for chat, camera or voice. The mobile help page lists no quick-note capture.
Structure: Pages and databases that you link yourself. Notion's help center has a guide to building a personal wiki, and templates to start from.
The catch: On iPhone you can't import data or select several blocks at once. The Free plan caps each uploaded file at 5 MB.

Notion gives you blocks and databases and leaves the system to you. That suits people who like to design: one database for notes, one for projects, one for the things you read, all linked. It also means nothing is set up on day one.

It is the one app on this list that Driftto writes to. How Driftto and Notion fit together.

Notion on the App Store

2 Obsidian

Dynalist Inc. · iPhone, iPad, Android, desktop

The pick if you want your notes as plain files you own, and don't mind building the rest.

Price: Free without limits. Sync costs $4 a month billed yearly, or $5 monthly. A commercial license, $50 a year, is optional.
Works on: iPhone, iPad, Android, Mac, Windows and Linux. The iPhone app needs iOS 15.6 or later.
Capture: Quick Capture from the Lock Screen, Control Center or a widget saves text without waiting for your vault to load. It needs iOS 26 and Obsidian 1.14.
Structure: Internal links and a graph view, on notes stored as Markdown files in a folder you pick.
The catch: Sync costs extra. Without it you rely on iCloud vaults or another file service that you set up yourself.

Obsidian keeps a vault of plain text files, and its own help page uses the words second brain for it. Links between notes are the core, and community plugins add the rest. Obsidian's Quick Capture does the same job as Driftto, so Driftto does not write there.

Obsidian on the App Store

3 Capacities

Capacities Labs · iPhone, iPad, Android, desktop, web

A second brain with the structure built in. Daily notes, object types and links are there on day one.

Price: The Basic plan is free, with 5 GB of media. Pro is $9.99 a month billed yearly, or $11.99 monthly, and adds AI, tasks and calendar.
Works on: iPhone, iPad, Android, Mac, Windows, Linux and the web.
Capture: Share sheet, widgets, Siri and Control Center save text, links and images. A quick note goes into today's daily note.
Structure: Everything is an object with a type, such as a person, a book or a project, and objects link to each other. The daily note works as an inbox.
The catch: The Basic plan leaves out AI, tasks, calendar and Readwise import. Capacities' docs call the phone app a companion to the desktop app.

Capacities replaces folders with object types. A book, a person and a project each get their own properties, and a note about a meeting links to all three. Its docs even have a page on PARA, Tiago Forte's way of sorting notes. Driftto does not write to Capacities.

Capacities on the App Store

4 Tana Outliner

Tana Labs · iPhone, iPad, Android

The most structured second brain here. Tags carry fields, and you build the setup yourself.

Price: Free covers the editor, 3 workspaces and 0.5 GB. Plus is $8 a month and Pro $14, monthly. The App Store sells them as $10 and $17.99.
Works on: iPhone and iPad (iOS 17 or later), and Android.
Capture: A Capture tab for text, voice, camera and files, plus Lock Screen and Home Screen widgets, Siri and Shortcuts. It saves to Today, Tomorrow or Inbox.
Structure: Supertags give a bullet a type and fields, and every date gets a daily note. Notes with the same supertag show as a table.
The catch: Tana is also the name of the company's meeting platform. This is Tana Outliner, and not every search query works on mobile.

Tana is an outliner where a note can be a task, a person or a book, depending on its tag. AI transcription of voice memos needs a paid plan. If you read about Tana as a note app, this is the product people mean. Driftto does not write to it.

Tana Outliner on the App Store

5 Apple Notes

Apple · iPhone, iPad, Mac

Better than you'd expect as a second brain: tags, Smart Folders and Quick Notes, with nothing to install.

Price: Included with iOS. iCloud keeps it in sync: 5 GB is free, 50 GB is $0.99 a month, 200 GB is $2.99.
Works on: iPhone, iPad and Mac, kept in sync by iCloud.
Capture: Quick Notes from Control Center on any screen, a scan of text and documents, and audio with a live transcript.
Structure: Folders, tags, and Smart Folders that filter on tags, dates and mentions. Quick Notes take links, images, tags and mentions.
The catch: Apple's guide describes folders, tags and Smart Folders, and no graph view. Audio transcription needs an iPhone 12 or later.

Most people already have years of notes here. Tags and Smart Folders turn that pile into something you can filter, and Quick Notes catch a thought over any app. Driftto does not write to Apple Notes. Quick Notes does that job.

Apple Notes on the App Store

6 Logseq

Logseq Inc. · iPhone, iPad, desktop

Free, open source and built around links between blocks. The weak part is the iPhone app.

Price: Free. The README asks for optional donations through Open Collective.
Works on: iPhone and iPad, and the desktop app. The App Store version needs iOS 14 or later.
Capture: The App Store listing names an audio recorder and to-dos, and no widget or Siri. I found no Logseq help page that says more.
Structure: Backlinks, a knowledge graph, and page and block references and embeds, on plain Markdown or Org-mode files.
The catch: The App Store version was last updated in April 2024. The README calls the newer mobile app alpha, and warns of data loss in the DB version.

Logseq works like Obsidian with an outline: every line is a block you can link to or embed. On a computer that is a strong second brain for free. On an iPhone, check that the app suits you before you move a library over. Driftto does not write to Logseq.

Logseq on the App Store

Getting things in Capture, the first step of a second brain.

7 Driftto

Made by me · iPhone

Type or say a thought once, and it lands as a new page in your Notion database. It writes nowhere else on this list.

Price: Free to download. $2.99 a month, $19.99 a year with a free week for new subscribers, or $29.99 once.
Works on: iPhone, with Siri, Home Screen and Lock Screen widgets, and a Control Center button.
Sends to: Notion, from this list. The whole note becomes the page title in your database, and a photo goes in as an image. No body text.
Structure: None. Driftto only adds new items. It never reads, edits or moves what is in Notion, so the structure stays yours.
The catch: It does not write to Obsidian, Capacities, Tana, Logseq or Apple Notes. Your second brain has to be a Notion one.

In Tiago Forte's four steps, Driftto is the first one, capture, and nothing more. You connect Notion once and pick the database. After that it is one screen: type or speak, tap Notion, and the note is a new page in your inbox. "Hey Siri, new capture in Driftto" does it without touching the phone.

I built it because the slow part of saving a thought was never the typing. It was the seconds before: unlocking, finding the app, finding the page. If your note needs a body as well as a title, write it in Notion itself. How Driftto and Notion fit together.

Driftto on the App Store

8 Readwise

Readwise · iPhone, iPad, web

Fills a second brain with what you read, not what you think. The Notion and Obsidian exports run on their own.

Price: Full Readwise is $9.99 a month billed yearly, after a 30-day trial. Highlights Lite is $5.59 and leaves out exports and tags.
Works on: An iPhone and iPad app, and the web. It imports from Kindle, Apple Books, Kobo and 40-plus more.
Sends to: Notion and Obsidian, on their own. A new book makes a new page, and later highlights are added at the bottom.
Review: Daily Review brings old highlights back in the app and by email. Highlights take tags and notes.
The catch: Export only appends. A highlight you change in Readwise afterwards isn't updated in Notion until you export that document again.

Readwise is the capture step for reading. Highlight in Kindle or a read-later app, and the text reaches your Notion or Obsidian without copying. It does not take notes you think up yourself, so it sits next to a capture app, not in place of one.

Readwise on the App Store

How I picked

An app made the list if it can hold a second brain on an iPhone: an iPhone app, a way to link notes, and search. Those apps were judged on how you capture on the phone and how notes connect. Capture apps on one thing: how few steps stand between a thought and a place in your second brain. On that criterion Driftto takes the fewest for Notion, so it leads that part and nothing else.

Reflect and Evernote are missing because I could not pin down a clear iPhone price from their own pages. Reflect has split into Reflect Classic and a new app, and Evernote's App Store listing shows more than one price for the same plan name. Nobody paid to be here and there are no affiliate links. For plain brain dumps, see the best brain dump apps. When a price or a feature changes, this page changes with it.

Questions

What is a second brain?

Tiago Forte's name for a digital place where you keep what you learn and where it came from. His method, Building a Second Brain, has four steps: capture, organize, distill and express. The apps above hold the notes. Capture is the step that gets them there.

Which app is best for a second brain?

It depends on how you like to work. Notion if you want to design the structure, Obsidian if you want plain files, Capacities if you want the structure ready made, Tana if you like outlines with typed notes, and Apple Notes if you want nothing to install.

Is Obsidian better than Notion for a second brain?

Neither is better. Obsidian keeps Markdown files in a folder you own and is free, with Sync at $4 a month. Notion keeps pages and databases in a workspace, and is free for one person. Pick files or databases.

How do I add notes to a second brain from my iPhone quickly?

Start with the app's own capture: Obsidian, Capacities and Tana all have Lock Screen or Home Screen capture. Notion's mobile help page lists no quick-note capture, so for Notion a capture app like Driftto takes fewer steps than opening Notion.

Driftto is in the App Store now.

Free to download. The yearly plan starts with a free week.