iOS app · v2.4 · local-first · App Store

Think less,
remember more.

Second Brain is an AI memory companion for iOS. Capture every passing thought by text or voice, and let AI classify, connect, and recall them for you — across three memory tiers shaped by how your mind actually works.

Download for iOS ↗ See how it works Free tier · 10 captures / day

captures · today auto-classified · on-device

Idea for the essay — "what local-first really costs." → filed: instant · auto-tag: writing, essay 14:02

Coffee with Marko — he's worried about the SDK migration. → filed: short-term · person: Marko 12:38

Helsinki Cathedral at sunrise — third year running. → promoted to long-term · theme: rituals 06:14

Press ⌘ N anywhere on iOS to capture. —

3tiers

memory drawers · neuroscience-shaped

On-device

apple foundation models · $0 / capture

0SDKs

analytics · telemetry · crash reporting

$4.99/ mo

pro tier · free tier always free

01 / app preview

See Second Brain in action.

Capture thoughts, explore memories with AI, track people, and reflect on your growth — all in one app.

Memory Capture — organize thoughts with AI

Capture01

Explore02

People03

Reflect04

Voice05

Themes06

02 / about

An AI memory companion for iOS, built in Helsinki.

Second Brain is an AI memory companion app for iOS, built by Smart Kiitös Oy in Finland. It captures your thoughts the moment they arrive — by text or voice — and uses on-device Apple Foundation Models together with the Anthropic Claude API for deeper exploration and reflection, classifying, connecting, and recalling them when you need them most. A three-layer memory system inspired by neuroscience moves notes from Instant to Short-term to Long-term storage, so quick fragments and lasting ideas each get their own home. Everything lives locally in SwiftData, with optional iCloud sync via your private CloudKit container — no analytics, no third-party servers, no training on your data. The free tier includes 10 captures and 3 explores per day; Second Brain Pro unlocks unlimited use for $4.99/month or $39.99/year.

03 / memory model

Three tiers, borrowed
from how your brain already works.

Every capture is classified on-device by Apple Foundation Models — instant → short-term → long-term — and graduates between tiers based on use, not on a cron job.

MEM_01 INSTANT

Fleeting thoughts

working drawer · ≤ 24h

Quick fragments, daily observations, things that pop into your head. AI processes these daily — promoting the important ones and archiving the rest.

"Great coffee place on Mannerheimintie"

"Check if the meeting was moved"

MEM_02 SHORT-TERM

Active context

active drawer · 1–30d

Goals, deadlines, project notes, and plans for the near future. These stay active for the week and feed into your weekly reflections.

"Prepare slides for Friday's presentation"

"Lisa mentioned she's moving to Berlin"

MEM_03 LONG-TERM

Core knowledge

archive drawer · ∞

Important experiences, values, life philosophies, and key relationships. These are your permanent memories — strengthened over time through reflection.

"My approach to difficult conversations"

"Career goal: build products that matter"

04 / features

Capture everything,
forget nothing.

Second Brain organizes your thoughts with AI so you can focus on what matters. Each feature does one thing well and stays out of the way until you want it.

F.01

AI Classification

Capture a thought and AI instantly classifies it — identifying the memory type, extracting tags, and generating a summary. All on-device, zero API cost.

F.02

Voice Capture

Press and hold to record. Real-time transcription fills your capture field with live waveform feedback. Supports multiple languages.

F.03

Explore Memory

Ask questions about your memories. Hybrid recall finds related memories through people, text, and semantic similarity — then AI synthesizes insights across them.

F.04

Weekly Reflections

AI reviews your memories on a schedule — daily processing, weekly theme analysis, and monthly deep reflections that reveal growth patterns in your thinking.

F.05

Memory Graph

See how your ideas connect. A force-directed graph visualizes relationships between memories based on semantic similarity and shared tags.

F.06

People Cards

Create cards for the people in your life. AI detects names in your memories and links them automatically — so you remember everything about everyone.

05 / privacy posture

Your memories
stay yours.

Second Brain is built with privacy at its core. Memories live on your device, not on our servers. Sync, if you turn it on, goes through your iCloud end-to-end. Smart Kiitös never sees a byte. There is no analytics SDK, no telemetry, no third-party server.

Read the full privacy policy ↗

Local SwiftDataalways · default
iCloud sync (E2E)optional · your iCloud only
Smart Kiitös serverthere is none — nothing to disable
Third-party analyticsnever installed
Crash reporting SDKnever installed
Advertising networknever installed

06 / pricing

Free tier you can
actually live in.

Second Brain is free with generous limits. Pro pays for the heavier AI work — deeper reflections, unlimited explorations, memory graph, theme discovery.

tier_01

Free

$0/ forever

Free forever, no card required

10 memory captures / day
AI classification (on-device)
3 memory explorations / day
3 people cards
Memory connection graph
Theme discovery
Weekly reflections
Data export

Start free

tier_02 PRO

Pro

$4.99/ month

or $39.99 / year (save 33%) · 3-day free trial

Unlimited memory captures
AI classification (on-device)
20 memory explorations / day
Unlimited people cards
Memory connection graph
Theme discovery
Deep weekly & monthly reflections
Data export & iCloud sync

Go Pro ↗

07 / faq

Frequently asked questions.

Anything we missed? Email [email protected].

What is Second Brain and who is it for?

Second Brain is an iOS app that captures and recalls your thoughts using AI. It's built for writers, researchers, designers, founders, and anyone who has more ideas than they can hold in their head — people who want to think out loud without losing what they said.

How does Second Brain protect my privacy?

All notes are stored locally in SwiftData on your device. Sync, when enabled, runs through your own private iCloud CloudKit container. We operate no servers that store your content, run no analytics, and never use your data to train AI models.

Which AI models does Second Brain use?

Second Brain uses Apple Foundation Models on-device for instant classification (zero API cost), and the Anthropic Claude API for cloud features such as fast Explore queries and deeper weekly reflections.

What is the three-layer memory system?

Inspired by how human memory works, captures flow through three layers: Instant (just-arrived raw thoughts), Short-term (recent notes still being shaped), and Long-term (consolidated, searchable knowledge). The app handles promotion automatically based on how you interact with each note.

How much does Second Brain Pro cost?

Second Brain is free with 10 captures and 3 AI explores per day. Pro removes those limits and unlocks weekly reflections for $4.99 per month or $39.99 per year, billed through the App Store.

Does Second Brain work offline?

Yes. Capturing notes, browsing memories, and on-device classification all work offline. Cloud-powered features (Explore queries, weekly reflections) require an internet connection because they call the Claude API.

Remember more. Think deeper.

Second Brain is on the App Store. Your AI memory companion — quietly building a sharper version of you.

Download on App Store

Think less, remember more.