Save anything, summarized
Bookmark any link. On-device extraction pulls the content, then optional AI writes a summary and tags.
Android · Free · Offline-first
Your private
Your private
knowledge vault
Private bookmarking with AI-powered summaries, smart notes, and video transcription — captured, organized, and kept entirely on your device.
Works offline No account Your data never leaves your phone
No account. No servers. Your notes and bookmarks stay on your phone — AI is optional and uses your own key.
Everything, in one vault
A second brain that never phones home
Save links, transcribe videos, and write rich notes — with optional AI you control. Ten features, zero lock-in.
Auto-transcribe videos
YouTube, TikTok, Instagram, Facebook and X reels become searchable text you can read, quote, and keep.
Smart Notes
Free-form rich text or checklists, with inline images and scheduled reminders that ping you on time.
AI Smart Format
One tap rewrites a note — Professional, Concise, Bullet points, Friendly, or grammar-only fixes.
Folders & collections
Group bookmarks and notes together into collections, and move items between them in a tap.
Fast search
Instant keyword search across everything — plus optional AI semantic search that finds by meaning.
Share to Brain Jotter
Hit share in any app and Brain Jotter is right there — the link is prefilled, ready to save.
Offline & private
Everything is stored locally, one file per item. It works with zero connection and no account, ever.
Backup & restore
Export your whole library to a single JSON file, and import it back on any device. You own your data.
Bring your own AI
OpenAI, Anthropic, Gemini or OpenRouter — every AI feature is opt-in and uses a key you provide.
A closer look
Built to feel calm and fast
← swipe to explore →
Opt-in intelligence
AI that respects your privacy
Brain Jotter works fully without any AI. Turn it on only when you want to — and stay in control of exactly what gets sent, and to whom.
OpenAI
Anthropic
Gemini
OpenRouter
- Off by default. The app is fully usable with cloud AI switched off.
- Your key, your bill. Paste your own provider API key — nothing is billed through us.
- Only what you choose. Just the text you format or summarize is sent — never your whole library.
- No Brain Jotter server. There's no account and no backend that ever sees your data.
Sideload in under a minute
Install Brain Jotter
Brain Jotter isn't on the Play Store yet, so you install the APK directly. Here's the whole flow.
-
Download the APK
Tap the download button on your Android phone to grab
BrainJotter.apk. -
Open the file
From your notification shade or the Files app, tap the downloaded
BrainJotter.apk. -
Allow install from this source
If Android asks, enable “Allow from this source” for your browser or Files app, then go back.
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Install & open
Tap Install, wait a moment, then open Brain Jotter and hit “Get Started”.
Android asks for “install unknown apps” because the app comes from outside the Play Store — normal for sideloaded apps. Requires Android 7.0+, about 87 MB of space.
Good questions
Frequently asked
Is Brain Jotter free?
Yes — completely free to download and use. The only thing that could ever cost money is optional cloud AI, and that's billed by your own AI provider using a key you add, never by us.
Is my data private?
Everything you save lives on your device — one file per bookmark and note. There's no account and no Brain Jotter server. Data only leaves your phone if you turn on an optional AI feature, and even then only the specific text you chose to process is sent to your provider.
Do I need an API key?
No. Bookmarking, notes, folders, reminders, backup and keyword search all work with no key at all. A key (OpenAI, Anthropic, Gemini or OpenRouter) is only needed for the optional AI extras: summaries, Whisper video transcription, Smart Format and semantic search.
Why does Android warn about “unknown apps”?
Because Brain Jotter is installed directly rather than through the Play Store. That prompt is Android's standard sideload confirmation — you allow your browser or Files app to install it once, and you're done.
Which video platforms can it transcribe?
YouTube, TikTok, Instagram, Facebook and X (Twitter), plus direct audio and video files. Captions are used when available; otherwise Whisper transcription runs when you've enabled cloud AI with an OpenAI key.
Is there an iPhone version?
Not yet — Brain Jotter is Android-only for now (Android 7.0 and up).
Start your private vault
Free, offline, and yours. Download Brain Jotter and keep everything worth remembering in one calm place.